In accordance with the logic of scientific research, a research methodology is being developed. It is a complex of theoretical and empirical methods, the combination of which makes it possible to study complex and multifunctional objects with the greatest reliability. The use of a number of methods allows for a comprehensive study of the problem under study, all its aspects and parameters.
I. Methods of empirical knowledge. They serve as a means of collecting scientific facts that are subject to theoretical analysis.
The empirical level of knowledge includes:
Observation of phenomena
Accumulation and selection of facts
Establishing connections between them.
The empirical level is the stage of collecting data (facts) about social and natural objects. At the empirical level, the object under study is reflected mainly from external connections and manifestations. The main thing for this level is factualizing activity. These problems are solved using appropriate methods:
1. Observation
It is an active cognitive process, based, first of all, on the work of human senses and his objective material activity, deliberate and purposeful perception of phenomena of the external world in order to study and find meaning in phenomena. Its essence is that the object being studied should not be influenced by the observer, that is, the object should be in normal, natural conditions. This is the simplest method, which, as a rule, acts as one of the elements in other empirical methods.
A distinction is made between direct (visual) observation, when information is obtained without the help of instruments, and indirect observation - information is obtained using instruments or automatically using recording equipment.
Observation as a means of cognition provides primary information about the world in the form of a set of empirical statements.
In everyday life and in science, observations should lead to results that do not depend on the will, feelings and desires of the subjects. To become the basis for subsequent theoretical and practical actions, these observations must inform us about the objective properties and relationships of really existing objects and phenomena.
In order to be a fruitful method of cognition, observation must satisfy a number of requirements, the most important of which are:
Planfulness;
Focus;
Activity;
Systematicity.
Observation is a purposeful perception of a phenomenon, during which the researcher receives specific factual material. At the same time, records (protocols) of observations are kept. Observation is usually carried out according to a pre-planned plan, highlighting specific objects of observation. The following stages of observation can be distinguished:
Definition of tasks and goals (why, for what purpose is the observation being carried out);
Selection of object, subject and situation (what to observe);
Choosing an observation method that has the least impact on the object under study and most ensures the collection of the necessary information (how to observe);
Selecting methods for recording what is observed (how to keep records);
Processing and interpretation of the information received (what is the result).
A distinction is made between included observation, when the researcher becomes a member of the group in which the observation is being conducted, and non-involved observation - “from the outside”; open and hidden (incognito); continuous and selective.
Observation is a very accessible method, but it has its drawbacks due to the fact that the results of observation are influenced by the personal characteristics (attitudes, interests, mental states) of the researcher.
2. Comparison
One of the most common methods of cognition. It is not without reason that it is said that “everything is known by comparison.” It allows you to establish similarities and differences between objects and phenomena.
For a comparison to be fruitful, it must satisfy two basic requirements:
Only such phenomena should be compared between which there can be a certain objective commonality.
To understand objects, their comparison must be carried out according to the most important, essential (in terms of a specific cognitive task) characteristics.
Using comparison, information about an object can be obtained in two different ways. Firstly, it can act as a direct result of comparison. Secondly, very often obtaining primary information is not the main goal of comparison; this goal is to obtain secondary or derivative information that is the result of processing primary data. The most common and important method of such processing is inference by analogy.
3.Measurement
It is a more accurate cognitive tool. Measurement is the procedure for determining the numerical value of a certain quantity using a unit of measurement. The value of this procedure is that it provides accurate, quantitative information about the surrounding reality. The most important indicator of the quality of a measurement and its scientific value is accuracy, which depends on the diligence of the scientist, on the methods he uses, but mainly on the available measuring instruments.
4. Experiment
An experiment is a specially organized test of a particular method or method of work to determine its effectiveness. The actual experiment is conducting a series of experiments (creating experimental situations, observing, managing the experience and measuring reactions.
The difficulties of the experimental method are that it is necessary to master the technique of its implementation perfectly. An experiment involves interfering with the natural conditions of existence of objects and phenomena or reproducing certain aspects of them in specially created conditions.
Experimental study of objects compared to observation has a number of advantages:
1) during the experiment, it becomes possible to study this or that phenomenon in its “pure form”;
2) the experiment allows you to study the properties of objects of reality under extreme conditions;
3) the most important advantage of the experiment is its repeatability.
Any experiment can be carried out either directly with an object or with a “substitute” for this object - a model.
The use of models makes it possible to apply the experimental research method to such objects, direct operation with which is difficult or even impossible. Therefore, modeling is a special method and is widely used in science.
5. Material modeling
Modeling is a method of studying objects using models, allowing one to obtain knowledge using substitutes (models) of real objects. A model is a mental or materially realized system that replaces another system with which it is in a state of similarity. The model replaces the object of study and has some common properties with the object being studied. Material models are made from real materials. The modeling method allows one to obtain information about the various properties of the phenomena under study based on experiments with models.
6. Survey methods - conversation, interview, questionnaire.
A conversation is an independent or additional research method used to obtain the necessary information or clarify what was not clear enough during observation. The conversation is conducted according to a pre-planned plan, highlighting issues that require clarification. It is conducted in free form without recording the interlocutor’s answers.
Interviewing is a type of conversation. When interviewing, the researcher adheres to pre-planned questions asked in a certain sequence. During the interview, responses are recorded openly.
Questioning is a method of mass collection of material using a questionnaire. Those to whom the questionnaires are addressed provide written answers to the questions. Conversations and interviews are called face-to-face surveys, while questionnaires are called correspondence surveys.
The effectiveness of conversations, interviews and questionnaires largely depends on the content and structure of the questions asked. The conversation plan, interview and questionnaire are a list of questions (questionnaire). Designing a questionnaire involves determining the nature of the information to be obtained; formulating an approximate series of questions that should be asked; drawing up the first plan of the questionnaire and its preliminary testing through a pilot study; correction of the questionnaire and its final editing.
II. Methods of theoretical research
Theoretical analysis is the identification and consideration of individual aspects, features, features, and properties of phenomena. By analyzing individual facts, grouping, systematizing them, we identify the general and special in them, and establish a general principle or rule. Analysis is accompanied by synthesis; it helps to penetrate into the essence of the phenomena being studied.
The theoretical level of cognition is associated with the predominance of mental activity, with the comprehension of empirical material and its processing. At the theoretical level it reveals
Internal structure and patterns of development of systems and phenomena
Their interaction and conditionality.
Theoretical methods are necessary to define problems, formulate hypotheses, and evaluate collected facts. Theoretical methods are associated with the study of literature: the works of classics; general and special works; historical documents; periodicals, etc.
Studying the literature makes it possible to find out which aspects and problems have already been sufficiently well studied, which scientific discussions are ongoing, what is outdated, and which issues have not yet been resolved. Working with literature involves the use of methods such as compiling a bibliography - a list of sources selected for work in connection with the problem under study; abstracting - a condensed summary of the main content of one or more works on a general topic; note-taking - keeping more detailed records, the basis of which is highlighting the main ideas and provisions of the work; annotation - a brief record of the general content of a book or article; citation - a verbatim recording of expressions, factual or numerical data contained in a literary source.
Methods used at the theoretical level of research:
1. Abstraction
This is a distraction from some properties of the objects being studied and highlighting those properties that are studied in this study. It has a universal character, because every step of thought is connected with this process or with the use of its result. The essence of this method consists in mental abstraction from unimportant properties, connections, relationships, objects and in the simultaneous selection and recording of one or more aspects of these objects that are of interest to the researcher.
There is a distinction between the process of abstraction and abstraction. The abstraction process is a set of operations leading to obtaining a result, i.e., to abstraction. Examples of abstraction include countless concepts that people operate not only in science, but also in everyday life: a tree, a house, a road, a liquid, etc. The process of abstraction in the system of logical thinking is closely related to other research methods and, above all, to analysis and synthesis.
2. Axiomatic
It was first used by Euclid. The essence of the method is that at the beginning of the reasoning a set of starting points is given that do not require proof, since they are completely obvious. These provisions are called axioms or postulates. A system of inferential judgments is constructed from axioms according to certain rules. The set of initial axioms and propositions (judgments) derived on their basis forms an axiomatically constructed theory.
3. Analysis and synthesis
Analysis is a method that is based on the process of decomposing an object into its component parts. When a scientist uses the method of analysis, he mentally separates the object being studied, that is, he finds out what parts it consists of, what its properties and characteristics are.
Synthesis is the combination of parts obtained during analysis into something whole. As a result of the use of synthesis, the knowledge obtained as a result of the use of analysis is combined into a single system.
Methods of analysis and synthesis in scientific creativity are organically interconnected and can take various forms depending on the properties of the object being studied and the purpose of the research.
Direct (empirical) analysis and synthesis are used at the stage of superficial familiarization with the object. In this case, the individual parts of the object are isolated, its properties are detected, the simplest measurements are taken, and the directly given data lying on the surface of the general is recorded.
Structural-genetic analysis and synthesis allow us to penetrate most deeply into the essence of an object. This type of analysis and synthesis requires isolating in a complex phenomenon those elements that represent the most important thing in them, their “cell”, which has a decisive influence on all other aspects of the essence of the object.
The historical method is used to study complex developing objects. It is used only where the history of the object becomes the subject of research in one way or another.
4. Idealization
This is the mental creation of concepts about objects that do not exist in nature, but for which there are prototypes in the real world. Examples of concepts that arose in the process of using the idealization method are “Ideal gas”, “Ideal solution”, “Point”. The idealization method is widely used not only in the natural sciences, but also in social disciplines.
5. Induction and deduction
Induction is a conclusion, reasoning from the “particular” to the “general”. Inference from facts to some general hypothesis.
The deductive method is based on obtaining a conclusion by reasoning from the general to the specific. That is, new knowledge about an object is obtained by studying the properties of objects of a given class.
6. Ascents from the abstract to the concrete
The ascent from the abstract to the concrete is a universal form of the movement of scientific knowledge, the law of reflecting reality in thinking. According to this method, the process of cognition is divided into two relatively independent stages.
At the first stage there is a transition from the sensory-concrete to its abstract definitions. A single object is dismembered and described using many concepts and judgments. It seems to “evaporate”, turning into a set of abstractions and one-sided definitions fixed by thinking.
The second stage of the process of cognition is the ascent from the abstract to the concrete. Its essence lies in the movement of thought from abstract definitions of an object to the concrete in cognition. At this stage, the original integrity of the object is restored, as it were, it is reproduced in all its versatility - but already in thinking.
Both stages of cognition are closely interconnected. The ascent from the abstract to the concrete is impossible without a preliminary “anatomization” of the object by thought, without an ascent from the concrete in reality to its abstract definitions. Thus, we can say that the method under consideration is a process of cognition, according to which thinking ascends from the concrete in reality to the abstract in thinking and from it to the concrete in thinking.
III. Mathematical and statistical methods are used to process the data obtained by survey and experiment methods, as well as to establish quantitative relationships between the phenomena being studied. They help evaluate the results of an experiment, increase the reliability of conclusions, and provide grounds for theoretical generalizations. The most common mathematical methods are registration, ranking, and scaling. Using statistical methods, the average values of the obtained indicators are determined: arithmetic mean; median - indicator of the middle; degree of dispersion - dispersion, or standard deviation, coefficient of variation, etc. To carry out these calculations, there are corresponding formulas and reference tables are used.
The results processed using these methods make it possible to show a quantitative relationship in different forms: graphs, diagrams, tables.
A good example is writing a term paper, where in the introduction you also have to list the methods of conducting research that were used when writing a scientific work.
In this article you will learn the definition of this concept, what types of scientific research methods there are in a thesis, which of them are recommended to be used in projects on certain topics, as well as the features of each method.
What are methods in a thesis?
The research method for the thesis project is the use of worldview principles in relation to cognitive processes.
To put it simply, research methodology is nothing more than a correlation of research data with other fundamental sciences, the main of which is philosophy.
Science uses a huge number of methods. But we will be specifically interested only in what methods are used in the thesis. And all because their choice directly depends on what goals and objectives were set in the work. Based on this, the student will determine the methods of thesis design.
Despite the huge number of methods in science, each will pursue a single goal: to find the truth, a correct understanding and explanation of the current situation, and in rare cases, even try to change it.
Classification
Research methods used in the thesis can be divided into:
- general (theoretical, universal) research methods in the thesis;
- private (empirical or practical) research methods in the thesis.
Let's take a closer look at each group in order to reasonably choose the right method to solve a specific problem.
Theoretical methods
These methods are universal and serve to systematize facts in scientific work.
When writing a thesis, the following methods are mainly used.
Analysis
The most commonly used method used in thesis work.
Methods of analysis in the thesis are designed to decompose the object or phenomenon being described into signs and properties in order to study it more specifically.
Examples include frequent comparisons of different artistic styles, car characteristics of different brands, and writers' styles of expressing thoughts.
Synthesis
In contrast to the previous method, synthesis is intended to combine individual elements (properties, characteristics) into a single whole for a more detailed study.
This research method is quite closely related to the method of analysis, since it is always present as the main element that unites the individual results of the analysis.
Modeling
With the modeling method, the object of study, which exists in reality, is transferred to an artificially created model. This is done in order to more successfully simulate situations and obtain results that would be difficult to achieve in reality.
Analogy
In analogy, a search is made for the similarity of objects and phenomena according to certain characteristics.
Deduction
The deduction method allows you to draw conclusions about certain phenomena and objects based on data on a large number of small (particular) features.
Induction
In contrast to the previous method, the inductive method encourages reasoning from the general picture to specific points.
Generalization
The generalization method is somewhat similar to deduction. Here a general conclusion is also made about objects or phenomena based on many small signs.
Experts distinguish:
- inductive generalization (empirical) – a transition from more specific properties/characteristics of an object/phenomenon to more general ones;
- analytical generalization - a transition from one opinion to another during the thought process, without applying empirical reality.
Classification
The classification method involves dividing an object or phenomenon into groups according to certain characteristics.
The main task of this method is to structure and make information clearer and easier to understand.
They can be classified based on different characteristics. For example, by:
- physical properties (weight, size, volume);
- material (plastic, wood, metal, porcelain);
- genres (sculpture, painting, literature);
- architectural styles.
They can also be classified according to geopolitical factors, chronological and other factors.
Abstraction
This method is based on the specification of a particular property of a phenomenon or object that needs to be studied as part of the study.
The essence of abstraction is to study a specific property of the object or phenomenon being studied, without taking into account all its other characteristics.
The abstraction method is one of the most important and basic research methods in a thesis in the humanities. With its help, the most important patterns in such sciences as pedagogy, psychology, and philosophy, invisible at first glance, were noted. A good example of abstraction is the division of literature into a huge variety of styles and genres
Formalization
The essence of the formalization method is to convey the structure or essence of a phenomenon or object in a symbolic model through the use of mathematical schemes, formulas, and symbols.
Specification
Concretization is understood as a detailed study of an object or phenomenon in real-life conditions.
Analogy
The essence of the analogy method is that, knowing certain properties and characteristics of an object or phenomenon, we can draw a certain line to another object or phenomenon similar to our object of study. As a result, we can come to certain conclusions.
This method is not 100% correct and does not always give reliable results. However, overall its effectiveness is quite high. Most often it is used in cases where certain objects or phenomena cannot be studied directly (for example, when studying terrestrial planets, when determining their properties, conditions for potential settlement by the Earth's population).
Different sciences use completely different research methods. But in any specialty and field of science, at least 2 will always be used in the thesis: synthesis and analytical research method
Practical (private) methods
In the thesis, along with theoretical methods, practical methods are used equally, depending on the object or phenomenon. Their peculiarity lies in a special way of studying information, collecting and processing it, and conducting experiments.
Particular research methods in the thesis are used directly to collect specific data about a phenomenon or object. These methods often help to describe and identify new phenomena and objects, find patterns or prove hypotheses.
Now let's get acquainted with the most popular practical methods when writing a thesis project.
Observation
The observation method in the thesis is based on an objective perception of reality to collect data on the properties and relationships of the objects of study.
Comparison
The comparison method is considered one of the most popular. It is used to compare two or more research objects based on one characteristic.
Measurement
The measurement method is quite accurate. It is based on determining the numerical values of certain indicators.
Experiment
The experimental method is interpreted as the reproduction of an observation or phenomenon under certain conditions.
An experiment can also serve as an experience, the purpose of which is to verify (refute or confirm) existing provisions. The main thing is that during the study two points should be present: evidence and repeatability. The fact is that the task of an experiment is not only to visually demonstrate or discover some property, but also to be able to reproduce it.
An excellent example of an experiment is Galileo's experiment with a cannonball and a lead ball to determine the speed of fall. Observation
This method opens up any scientific knowledge, which is why it is key when conducting any research.
The essence of the observation method is to observe the object of study and record any important changes or positions (reactions, properties).
Measurement
The measurement method is one of the most effective. We are talking about fixing any physical parameters of the object of study (volume, height, weight, length, etc.) using units of measurement.
The result obtained by applying this method will be recorded in a numerical value.
Modeling
In a general sense, a model is a structured, reduced image of something, an imitation of one or more objects.
Modeling can be:
- objective (when reproducing a separate part of an object);
- symbolic (when using formulas, drawings, diagrams, etc.);
- mental (when performing operations in the virtual world or mentally).
Modeling is indispensable when developing new technologies, designing cars, structures, etc.
Conversation and interview
The essence of both methods is to find a person who has any valuable information about the subject of study.
Many people may not see the difference between a conversation and an interview. The latter is distinguished by a more structured and regulated procedure: during the interview, the interlocutor answers clearly posed questions that were prepared in advance. In addition, the person asking the questions does not demonstrate his opinion in any way.
The conversation is casual in nature. Here both participants in the conversation can freely express their opinions and ask questions, even spontaneously Survey and questionnaire
These methods also have much in common with each other. The essence of both lies in the preliminary preparation of questions to which answers should be obtained. As a rule, respondents are given several answer options to choose from.
The main difference between a survey and a questionnaire is the form of conducting it. The survey, as a rule, can be oral or written. But surveying is possible only in written form or on a computer medium. Often during a survey, the answer can be given in graphical form.
The advantage of these practical methods in the diploma is the large audience coverage. And if many people are surveyed, then the chances of getting more accurate data are much higher.
Description
Experts note the similarity of the description method with the observation method. When conducting research using the descriptive method, not only behavior and phenomena are recorded, but also the appearance and characteristics of the object of study.
Other private methods
Depending on the direction of the student’s specialization, the following private, highly specialized research methods can be used:
- Economy . Analysis: positive, normative, functional, static, dynamic. Economic and mathematical modeling. Method of financial ratios. Scenario method for forecasting economic phenomena. Method of unity of historical and logical. Construction of economic hypotheses. The “other things being equal” method.
- Pedagogy/Psychology . Studying the products of students' creativity. Interview. Conversation. Study of group differentiation. Participant observation. Pedagogical control tests (testing). Questionnaire (survey). Ranging. Scaling. Registration.
- Philology . Analysis: compositional, discourse, motive, intertextual, distributional, contextual, semantic. Linguistic experiment. Biographical method. Content analysis. Lexicographic statistics. Differential analysis of oppositions. Narrative method. Dichotomy. Transformational synthesis and analysis. "Concrete Literary Studies". Semiotic method.
Other methodology
Academician A.Ya. Flier identified a slightly different system of methods used in writing dissertations. In his opinion, all methods are divided into humanitarian and social-scientific.
Humanitarian methodologies
- Historical- describes the history of culture in accordance with the principle of building a linear chronological sequence of its events and phenomena.
- Hermeneutic- explores culture by revealing (deciphering) the original meanings of cultural phenomena inherent in them during creation.
- Phenomenological- interprets the historical facts of culture from the point of view of their appearance to the observer and seeks in them meanings that are relevant outside the historical context.
- Historical-psychological- studies the historical dynamics of culture from the point of view of identifying stable stage (civilizational) types of socially conditioned consciousness and mental state in it.
- Cultural symbolism and poststructuralism- an eclectic methodology that interprets the material within a contextual framework established for various reasons by the authors of the studies themselves, and treats it as inevitably incomplete in its symbolic and semantic cognition.
Social scientific methodologies
- Evolutionism is a study of the history of culture from the standpoint of recognition of its progressive development through the gradual complication of its structures (branches of evolutionism; formation theory, diffusionism, neo-evolutionism, cultural materialism).
- Cyclic and wave models of cultural dynamics - a description of cultures as separate “self-sufficient organisms” (civilizations) and the processes occurring in them as closed cycles or repeating wave movements.
- Structural functionalism is the interpretation of cultural and historical processes as functional, solving some immanent social problems to satisfy the interests and needs of people.
- Structuralism is a description of cultural and historical objects from the point of view of searching for the relationship between material and conceptual aspects in them, analysis of the structure of culture as a system of signs.
- Borderline methodologies that define new problem areas of cultural and historical science, postmodernism.
How to write methods in a thesis
Great! Now we know what methods exist. If we're lucky, we even understand what methods we can use in our work.
Standard speech structures when formulating methodology and research methods:
- This work is based on the provisions... methodology,
- the work is based on the provisions... methodology,
- the methodological basis/base of the study was the provisions of ... methodology,
- The following methods were used in the research/work..., research methods are... etc.
Next, it is worth indicating which figures were studying this problem. And in the history of the study, you can mention the historical context, tell what the newest authors managed to add to the existing data. Remember to mention scientists in chronological order!
There are also standard constructions used when describing research methods:
- the study of... dates back to...,
- in ... century ... were studied and described in detail ...,
- problems... dealt with...,
- a huge contribution to the development of the problem... made.../made work/research/work...,
- work is of great importance...
- works of recent years allow us to talk about...,
- the experience of history... shows that...,
- Currently the dominant point of view is...
- This approach is typical for...,
- The study of this issue began with the works..., in the works...,
- a prominent place in the works... occupies the position of...,
- Among the problems being developed in this direction we can name...,
- ……. covered in detail in the works...,
- connection...shown in...etc.
When writing a conclusion, you should focus on describing the structure of work with the following standard structures:
- all of the above determined the structure of the work, which consists of introduction, ... chapters, conclusion, bibliography, appendix (the latter is indicated if the work has an appendix);
- the logic, goals and objectives of the study determined the structure of the work, which consists of...;
- the introduction gives a general description of the work, substantiates the relevance of the topic and its social significance, defines the purpose, objectives, methodological basis of the study and research methods, and also gives a brief overview of the development of the problem;
- The first chapter is dedicated to...,
- the second chapter discusses/talks about..., the first chapter examined..., the second chapter begins with..., then...;
- the conclusion represents the conclusions of the work / the conclusion contains the main conclusions, etc.
An example of a description of methods in a thesis
Topic: prevention of dysgraphia in children with general speech underdevelopment
Purpose of the study: to identify the prerequisites for the occurrence of dysgraphia in children of senior preschool age with OSD and children without speech pathology.
In accordance with the goal and the formed hypothesis, the following research objectives were identified:
- Study of the theoretical and methodological aspect of the research problem based on data from specialized literature.
- Theoretical justification and development of experimental research methodology.
- Experimental study of the state of different aspects of oral speech and mental processes and functions that ensure the formation of written speech, determination of the typology of identified deficiencies in preschool children with ODD.
- Processing of the obtained experimental data
- Development of a set of methodological techniques for differentiated correctional and speech therapy work aimed at developing the prerequisites for written speech in children with SLD.
In accordance with the intended purpose and objectives of the study, we identified the following methods:
- Theoretical analysis of pedagogical, psychological and methodological literature on the research topic.
- Observation.
- Conversation, questioning.
- Analysis of children's activity products.
- Study of medical and pedagogical documentation.
- An experimental method, including conducting a confirmatory experiment, analyzing and summarizing the data obtained.
Conclusion
These are not all the methods that can be used when writing scientific papers. But we tried to introduce you to the most popular and important ones.
When choosing methods, remember: they must be scientifically sound and modern. Using outdated methods is unacceptable. In addition, the methods must be consistent with the research objectives, because solving each individual problem requires a specific method.
And it's completely okay that you don't know them all. Why, when there is a special one? Knowing such things is the job of specialists. And your task is to get everything you can from life and youth!
Data input and output can be done in three different ways (Figure 11.1)
Rice. 11.1. I/O Methods
1. I/O control is carried out by the CPU– software channel for data exchange between OP and VU
2. I/O control is carried out by special additional equipment - direct access channel.
1. Programmable I/O (readiness polling mode). Synchronous control. The simplest method consists in the fact that the user program issues a system request, which the kernel translates into a call to the procedure of the corresponding driver. The driver then begins the I/O process. During this time, the driver executes a very short program loop, constantly polling the readiness of the device it is working with (usually there is some bit that indicates that the device is still busy). When the I/O operation completes, the driver places the data where it is needed and returns to its original state. The operating system then returns control to the program that made the call. This method is called waiting for readiness or active waiting and has one drawback: the processor must poll the device until it completes its work.
The set of commands used includes I/O commands belonging to the following categories.
● Control. Commands in this category are used to actuate an external device and tell it what to do. For example, a magnetic tape unit can be commanded to rewind or move forward one record.
● State. Used to check the status of the I/O controller and related peripherals.
● Broadcast. Used to read and/or write data to and from processor registers and external devices.
2. Interrupt communication mode (asynchronous control). At the second way The driver starts the device and asks it to issue an interrupt when the I/O is completed. After this, the driver returns the data, the operating system blocks the calling program, if necessary, and begins to perform other tasks. When the controller detects the end of a data transfer, it generates an interrupt to signal the completion of the operation.
The I/O process in this case consists of the following steps (Fig. 11.2):
Rice. 11.2. Interrupt driven I/O
step 1. The driver transmits the command to the controller by writing information to the device registers. The controller then starts the device
step 2 . When the controller finishes reading or writing the number of bytes it was told to transfer, it sends a signal to the interrupt controller chip using specific bus wires.
step 3 . If the interrupt controller is ready to receive an interrupt (which it may not be if it is busy with a higher priority interrupt), then it sends a signal to a specific processor pin informing the CPU.
step 4 . The interrupt controller places the device number on the bus so that the central processor can read it and find out which device has just completed its work (after all, several devices can work at the same time).
Once the CPU has decided to accept the interrupt, the contents of the program counter (PC) and processor status word (PSW) are pushed onto the current stack, and the processor switches to kernel mode. The device number can be used as an index to a part of memory used to find the address of the interrupt handler for a given device. This part of memory is called interrupt vector. When the interrupt handler (the part of the device driver that sent the interrupt) begins its work, it removes the program counter and processor status word located on the stack, saves them, and queries the device for information about its state. After interrupt processing is completely completed, control returns to the previously running user program, to the command whose execution has not yet been completed.
In order not to lose connection with the device, a time countdown can be started, during which the device must execute the command and issue an interrupt request signal.
The maximum time interval during which an I/O device or its controller must issue an interrupt request signal is often called setting a timeout .
If this time expires after issuing the next command to the device, and the device still does not respond, then it is concluded that communication with the device is lost and it is no longer possible to control it. The user and/or process receives an appropriate diagnostic message.
Drivers operating in interrupt mode, are a complex set of software modules and can have several sections:
● launch section,
● one or more continuation sections
● and completion section.
Launch section initiates an I/O operation. This section is run to turn on an I/O device or simply to initiate another I/O operation.
Continuation section(there may be several of them if the data exchange control algorithm is complex and several interrupts are required to perform one logical operation) carries out the main work of data transfer.
The continuation section, in fact, is the main interrupt handler.
The interface used may require several sequences of control commands to control I/O, and the device usually only has one interrupt signal.
Therefore, after executing the next interrupt section, the interrupt supervisor must transfer control to another section at the next ready signal.
This is done by changing the interrupt processing address after executing the next section; if there is only one interrupt section, then it itself transfers control to one or another processing module.
Completion section usually turns off the I/O device or simply ends the operation.
Managing I/O operations in interrupt mode requires more effort on the part of system programmers - such programs are more difficult to write than those that operate in polling mode.
An example of this is the situation with drivers that provide printing. Thus, in Windows OS (both Windows 9x and Windows NT), the parallel port print driver does not operate in interrupt mode, as is done in other operating systems, but in readiness polling mode, which leads to 100% CPU load on all the time printing. At the same time, naturally, other tasks launched for execution are also executed, but solely due to the fact that Windows OS implements preemptive multitasking and from time to time interrupts the print management process and transfers the central processor to other tasks.
3. Direct memory access.Third method I/O information consists of using a special direct memory access controller (DMA, Direct Memory Access), which manages the flow of bits between RAM and some controllers without constant intervention from the central processor. The processor calls the DMA chip, tells it how many bytes to transfer, tells it the device and memory addresses, as well as the direction of data transfer, and allows it to proceed on its own. Upon completion of work, the DMA initiates an interrupt, which is processed in the same way as described above.
The operating system can only use direct memory access if it has a hardware DMA controller, which most systems have. Typically, a DMA controller installed on the motherboard handles data transfer requests from several different I/O devices, often in a concurrent manner.
Wherever it is physically located, the DMA controller can access the system bus independently of the CPU ( rice. 11.3). It contains several registers that can be read and written by the CPU.
Rice. 11.3. I/O using direct access
These include a memory address register, a byte counter, and one or more control registers. Control registers specify:
which I/O port should be used,
direction of data transfer (reading from or writing to an I/O device),
transfer unit (transfer data byte-by-byte or word-by-word),
number of bytes to be transferred in one operation.
First, the central processor programs the DMA controller, setting its registers and thus indicating what data should be moved where ( step 1 in fig. 11.3).
The processor then instructs the disk controller to read the data into the internal buffer and verify the checksum. Once the data has been received and verified by the disk controller, DMA can begin operation.
The DMA controller begins data transfer by sending a read request to the disk controller via the bus ( step 2). This read request looks like a normal read request, so the disk controller doesn't even know whether it came from the CPU or the DMA controller. Typically the memory address is already on the address bus, so the disk controller always knows where to send the next word from its internal buffer.
Memory writes are another standard bus cycle ( step 3).
When the recording is complete, the disk controller also sends an acknowledgment signal to the DMA controller via the bus ( step 4).
The DMA controller then increments the memory address being used and decrements the byte counter.
After this, steps 2 to 4 are repeated until the counter value becomes zero.
Scientific research can be defined as purposeful knowledge. Conducting research means studying, cognizing patterns, systematizing facts.
Scientific research has a number of distinctive features: the presence of a clearly formulated goal; the desire to discover the unknown; systematic process and results; justification and verification of the obtained conclusions and generalizations.
It is necessary to distinguish between scientific and everyday knowledge. Scientific knowledge, unlike everyday knowledge, involves the use of special research methods. In this regard, there is a need to constantly search for new methods for studying unexplored objects.
What are research methods
Research methods are ways of achieving goals in scientific work. The science that studies these methods is called “Methodology”.
Any human activity depends not only on the object (what it is aimed at) and the actor (subject), but also on how it is carried out, what means and methods are used. This is the essence of the method.
Translated from Greek, “method” means “way of knowing.” A correctly chosen method contributes to faster and more accurate achievement of the goal and serves as a special compass that helps the researcher avoid most mistakes while making his way.
The difference between method and technique and methodology
Very often there is confusion in the concepts of method and methodology. A methodology is a system of ways of knowing. For example, when conducting sociological research, quantitative and qualitative methods can be combined. The entire set of these methods will constitute a research methodology.
The concept of methodology is close in meaning to the research procedure, its sequence, and algorithm. Without a high-quality methodology, even a correctly selected method will not give a good result.
If methodology is a way of implementing a method, then methodology is the study of methods. In a broad sense, the methodology is
Classification of scientific research methods
All methods of scientific research are divided into several levels.
Philosophical methods
The most famous among them are the most ancient methods: dialectical and metaphysical. In addition to them, philosophical methods include phenomenological, hermeneutic, intuitive, analytical, eclectic, dogmatic, sophistic and others.
General scientific methods
Analysis of the process of cognition makes it possible to identify the methods on which not only scientific, but also any everyday human cognition is built. These include theoretical level methods:
- Analysis is the division of a single whole into separate parts, sides and properties for their further detailed study.
- Synthesis is the combination of individual parts into a single whole.
- Abstraction is the mental selection of any essential properties of the subject under consideration while simultaneously abstracting from a number of other inherent features.
- Generalization is the establishment of a unifying property of objects.
- Induction is a method of constructing a general conclusion based on known individual facts.
Examples of research methods
For example, by studying the properties of certain liquids, it is revealed that they have the property of elasticity. Based on the fact that water and alcohol are liquids, they conclude that all liquids have the property of elasticity.
Deduction– a way of constructing a particular conclusion based on a general judgment.
For example, two facts are known: 1) all metals have the property of electrical conductivity; 2) copper is a metal. We can conclude that copper has the property of electrical conductivity.
Analogy- a method of cognition in which knowledge of a number of common characteristics of objects allows one to draw a conclusion about their similarity based on other characteristics.
For example, science knows that light has properties such as interference and diffraction. In addition, it was previously established that sound has the same properties and this is due to its wave nature. Based on this analogy, a conclusion was made about the wave nature of light (by analogy with sound).
Modeling– creation of a model (copy) of the object of study for the purpose of its research.
In addition to methods at the theoretical level, there are methods at the empirical level.
Classification of general scientific methods
Empirical Methods
| Method | Definition | Example |
| Observation | Research based on the senses; perception of phenomena | In order to study one of the stages of children's development, J. Piaget observed children's manipulative games with certain toys. Based on observation, he concluded that the child’s ability to put objects together appears later than the motor skills necessary for this. |
| Description | Recording information | The anthropologist records all the facts of the life of the tribe without exerting any influence on it |
| Measurement | Comparison based on general characteristics | Determining body temperature using a thermometer; determining weight by balancing weights on lever scales; determining distance using radar |
| Experiment | Research based on observation in conditions created specifically for this purpose | On a busy city street, groups of people in various numbers (2,3,4,5,6, etc. people) stopped and looked up. Passers-by stopped nearby and also began to look up. It turned out that the percentage of those who joined increased significantly when the experimental group reached 5 people. |
| Comparison | Research based on the study of similarities and differences between objects; comparison of one object with another | Comparison of economic indicators of the base year with the past, on the basis of which a conclusion is drawn about economic trends |
Theoretical level methods
| Method | Definition | Example |
| Formalization | Revealing the essence of processes by displaying them in a symbolic form | Flight simulation based on knowledge of the main characteristics of the aircraft |
| Axiomatization | Application of axioms to construct theories | Euclid's geometry |
| Hypothetico-deductive | Creating a system of hypotheses and drawing conclusions from this | The discovery of the planet Neptune was based on several hypotheses. As a result of their analysis, it was concluded that Uranus is not the last planet of the solar system. The theoretical justification for finding a new planet in a certain place was then confirmed empirically |
Specific scientific (special) methods
Any scientific discipline uses a set of specific methods that belong to different “levels” of methodology. It is quite difficult to tie any method to a specific discipline. However, each discipline relies on a number of methods. Let's list some of them.
Biology:
- genealogical - the study of heredity, compilation of pedigrees;
- historical - determining the relationship between phenomena that took place over a long period of time (billions of years);
- biochemical – the study of the chemical processes of the body, etc.
Jurisprudence:
- historical and legal – gaining knowledge about legal practice, legislation in different periods of time;
- comparative legal – search and study of similarities and differences between state legal institutions of countries;
- legal sociological method – research of reality in the field of state and law using questionnaires, surveys, etc.
In medicine, there are three main groups of methods for studying the body:
- laboratory diagnostics – study of the properties and composition of biological fluids;
- functional diagnostics – study of organs according to their manifestations (mechanical, electrical, sound);
- structural diagnostics – identifying changes in the structure of the body.
Economy:
- economic analysis - the study of the components of the whole being studied;
- statistical-economic method – analysis and processing of statistical indicators;
- sociological method - questionnaires, surveys, interviews, etc.
- design and calculation, economic modeling, etc.
Psychology:
- experimental method - creating circumstances that provoke the manifestation of any mental phenomenon;
- observation method - a mental phenomenon is explained through organized perception of a phenomenon;
- biographical method, comparative genetic method, etc.
Analysis of empirical research data
Empirical research is aimed at obtaining empirical data - data obtained through experience and practice.
The analysis of such data occurs in several stages:
- Description of the data. At this stage, summarized results are described using indicators and graphs.
- Comparison. Similarities and differences between the two samples are identified.
- Studying dependencies. Establishing interdependencies (correlation, regression analysis).
- Reducing volume. Studying all variables if there are a large number of them, identifying the most informative ones.
- Grouping.
The results of any research conducted - analysis and interpretation of data - are drawn up on paper. The range of such research works is quite wide: tests, abstracts, reports, coursework, theses, theses, dissertations, monographs, textbooks, etc. Only after a comprehensive study and evaluation of the findings are the research results used in practice.
Instead of a conclusion
A. M. Novikov and D. A. Novikova in the book “” also distinguishes methods-operations (a way to achieve a goal) and methods-actions (solving a specific problem) in methods of theoretical and empirical research. This specification is not accidental. A more rigid systematization of scientific knowledge increases its effectiveness.
Research methods as they are updated: February 15, 2019 by: Scientific Articles.Ru
Debugging a program in any case requires thinking and logical comprehension of all available information about the error. Most errors can be detected by indirect evidence through a thorough analysis of program texts and test results without obtaining additional information. Various methods are used:
Manual testing;
Induction;
Deduction;
Trackback.
Manual testing method. This is the simplest and most natural method of this group. If an error is detected, you must execute the program under test manually, using the test suite during which the error was discovered.
The method is very effective, but is not applicable for large programs, programs with complex calculations, and in cases where the error is due to the programmer's incorrect understanding of how to perform certain operations.
This method is often used as part of other debugging methods.
Induction method. The method is based on a careful analysis of error symptoms, which may appear as incorrect calculation results or as an error message. If the computer simply freezes, then a fragment of the error manifestation is calculated based on the last results obtained and the user’s actions. The information obtained in this way is organized and carefully studied by viewing the corresponding fragment of the program. As a result of these actions, hypotheses about errors are put forward, each of which is tested. If the hypothesis is correct, then the information about the error is detailed, otherwise, another hypothesis is put forward. The sequence of debugging using the induction method is shown in Fig. 3 in the form of an algorithm diagram.
Figure 3 - Scheme of the induction debugging process
The most critical stage is identifying the symptoms of the error. When organizing data about an error, it is advisable to write down everything that is known about its manifestations, and record both situations in which a fragment with an error is executed normally, and situations in which the error manifests itself. If, as a result of studying the data, no hypotheses emerge, then additional information about the error is needed. Additional information can be obtained, for example, by performing similar tests.
In the process of proof, they try to find out whether all manifestations of an error are explained by a given hypothesis; if not all, then either the hypothesis is incorrect or there are several errors.
Deduction method. Using the deduction method, a variety of reasons are first formed that could cause this manifestation of an error. Then, analyzing the reasons, exclude those that contradict the available data. If all causes are excluded, then additional testing of the fragment under study should be performed. Otherwise, they try to prove the most probable hypothesis. If the hypothesis explains the received symptoms of an error, then the error is found, otherwise the next reason is checked (Fig. 4).
Figure 4 - Diagram of the debugging process using the deduction method
Trackback method. For small programs, the backtracking method is effective. They start from the point where they produce the wrong result. For this point, a hypothesis is built about the values of the main variables that could lead to obtaining the existing result. Next, based on this hypothesis, proposals are made about the values of the variables at the previous point. The process continues until the cause of the error is discovered.