Scientific validity definition

Validity and Reliability - How to Know if the Research is Correct?

The principles of validity and reliability are fundamental cornerstones of the scientific method.

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Types of Validity
Definition of Reliability
Content Validity
Construct Validity
External Validity

Together, they are at the core of what is accepted as scientific proof, by scientist and philosopher alike.

By following a few basic principles, any experimental design will stand up to rigorous questioning and skepticism.

What is Reliability?

The idea behind reliability is that any significant results must be more than a one-off finding and be inherently repeatable.

Other researchers must be able to perform exactly the same experiment, under the same conditions and generate the same results. This will reinforce the findings and ensure that the wider scientific community will accept the hypothesis.

Without this replication of statistically significant results, the experiment and research have not fulfilled all of the requirements of testability.

This prerequisite is essential to a hypothesis establishing itself as an accepted scientific truth.

For example, if you are performing a time critical experiment, you will be using some type of stopwatch. Generally, it is reasonable to assume that the instruments are reliable and will keep true and accurate time. However, diligent scientists take measurements many times, to minimize the chances of malfunction and maintain validity and reliability.

At the other extreme, any experiment that uses human judgment is always going to come under question.

For example, if observers rate certain aspects, like in Bandura’s Bobo Doll Experiment, then the reliability of the test is compromised. Human judgment can vary wildly between observers, and the same individual may rate things differently depending upon time of day and current mood.

This means that such experiments are more difficult to repeat and are inherently less reliable. Reliability is a necessary ingredient for determining the overall validity of a scientific experiment and enhancing the strength of the results.

Debate between social and pure scientists, concerning reliability, is robust and ongoing.

What is Validity?

Validity encompasses the entire experimental concept and establishes whether the results obtained meet all of the requirements of the scientific research method.

For example, there must have been randomization of the sample groups and appropriate care and diligence shown in the allocation of controls.

Internal validity dictates how an experimental design is structured and encompasses all of the steps of the scientific research method.

Even if your results are great, sloppy and inconsistent design will compromise your integrity in the eyes of the scientific community. Internal validity and reliability are at the core of any experimental design.

External validity is the process of examining the results and questioning whether there are any other possible causal relationships.

Control groups and randomization will lessen external validity problems but no method can be completely successful. This is why the statistical proofs of a hypothesis called significant, not absolute truth.

Any scientific research design only puts forward a possible cause for the studied effect.

There is always the chance that another unknown factor contributed to the results and findings. This extraneous causal relationship may become more apparent, as techniques are refined and honed.

Conclusion

If you have constructed your experiment to contain validity and reliability then the scientific community is more likely to accept your findings.

Eliminating other potential causal relationships, by using controls and duplicate samples, is the best way to ensure that your results stand up to rigorous questioning.

How to ace the HSC extended response section!

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Key Points Summary

Accuracy: to how well the results of your experiment reflect the expected outcome
Validity: how well you have controlled your experimental variables in order to maintain a fair test
Reliability: how many times you repeat the experiment and come to similar results

Content

Accuracy

Accuracy refers to how well the results of your experiment reflect the expected outcome. A lot of the time this has to do with your equipment and how well it works

Lets take the example of weighing a cat. If I place a cat onto a scale and the scale reads 4kg I can assume that this is accurate as this is roughly what I expect my cat to weigh. However, if I put my cat onto a scale at the scale reads 100kg then I can assume that my scale is inaccurate because this result is drastically different to what is reasonable to expect.

Validity

Validity is about how well you have controlled your experimental variables in order to maintain a fair test. In science experiments, we are concerned with 3 variables, our independent, dependent and control variables.

Dymocks Tip: Think V alidity has an V for Variables

To explore this concept, let’s consider the following example:

I am interested in measuring the effect of sunlight exposure on plant growth. I have three plants and I place one outside directly in the sun, one in a room with moderate sunlight and the other in a cupboard with no sunlight.

Variable	Definition/ Description	Relation to Experiment Example
Independent Variable	This is the things that you change in your experiment and are interested in how this change affects results. In a valid experiment there is only one independent variable.	For example, in my experiment, the thing I am changing is how much light each plant is exposed to.
Dependent Variable	This is the thing that you are measuring	For example, in my plant experiment, I am measuring how tall my plants grow in centimetres.
Control Variable	This is everything else that must be kept the same in order to maintain a fair test. This is important so that we can conclude that the effect we are observing is because of our independent variable and not some other factor.	For example, in my plant experiment I should water all the plants the same, use the same soil to plant them in, use the same plant seed etc.That way I can say that any changes in plant growth can only be due to their different sunlight exposure as all else in the experiment was kept the same.

Lets take a look at a sample NESA HSC question testing validity:

Answer: C

The experiment is invalid because there is more than one independent variable. For a valid test we need to have only 1 thing we change (i.e., only 1 independent variable), which in this case would be the amount of pollutant exposure. Everything else must be kept the same (i.e. our control variables). The amount of water, for example, is a control variable and needs to be kept the same.

Reliability

Reliability is how many times you repeat the experiment and come to similar results. If results of an experiment are consistent across many repetitions, then the experiment is deemed reliable.

For example, if I repeat an experiment 10 times and get similar results each time, then I can be confident that my results are reliable.

In scientific literature, the best way to determine the reliability of results to undergo a peer review process. This is when someone else repeats your experiment and gets the same results.

Dymocks Tip: Think Reliability has an R for Repeats

Conclusion

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Reliability of the scientific provisions of the dissertation

Reliability of scientific statements, conclusions and recommendations

One of the main sections of the introduction in the abstract and dissertation is the validity and reliability of scientific provisions, conclusions and recommendations.

In this section, the applicant must show that the provisions, conclusions and recommendations set out in the dissertation research are reliable, that is, objectively exist, and are not the result of erroneous constructions and conclusions of the applicant.
In order for the dissertation council to have reason to trust the research of the applicant, it is necessary that the provisions, conclusions and recommendations of the dissertation work are always reliably confirmed within the framework of the object under study for the entire class of research subjects, that is, under the same conditions, the same results.
Various methods can be used to validate the validity. Firstly, the work must confirm the reliability of information about the subject under study. This confirmation is based on a comprehensive analysis of previously performed research works on the subject of research, the use of a proven scientific and methodological apparatus in research (these questions are given in the introduction to the author's abstract and dissertation in the sections "The degree of development of the research problem" and "Research methods").

Reliability can be confirmed by verification, that is, when similar work is carried out at many objects, confirmation of the same result.
In addition, there are the following methods of evidence of reliability: analytical, experimental and confirmation by practice.
Analytical methods of verification of reliability are used in the presence of mathematical models in the research (economic-mathematical, social, etc.), which allow mathematical description of the processes under study.
Experimental validation methods are carried out by comparing theoretical and experimental results.
When confirming scientific results by practice, the coincidence of phenomena in practice with constructed theoretical provisions is considered.
In addition, the reliability is confirmed by the presence and volume of the source material and the approbation of research results in practice.
Below are examples of the reliability of scientific provisions in economics, law, pedagogy, psychology, philosophy, history .

Reliability of the scientific provisions of the research in the specialty Differential Equations, Dynamic Systems and Optimal Control (01.01.02) :

View reliability of results Differential equations, dynamical systems and optimal control

Reliability of the scientific provisions of the research in the specialty Theory of Probability and Mathematical Statistics (01.01.05) :

View the reliability of the results Probability theory and mathematical statistics

Reliability of the scientific provisions of the study in the specialty Computational Mathematics (01.01.07) :

View reliability of results Computational Mathematics

Reliability of the scientific provisions of the research in the specialty Discrete Mathematics and Mathematical Cybernetics (01.01.09) :

View results reliability Discrete Mathematics and Mathematical Cybernetics

Reliability of the scientific provisions of the research in the specialty Theoretical Mechanics (01. 02.01) :

View reliability of results Theoretical Mechanics

Reliability of the scientific provisions of the research in the specialty Mechanics of a deformable solid body (01.02.04) :

View the reliability of the results Solid Mechanics

Reliability of the scientific provisions of the research in the specialty Mechanics of liquid, gas and plasma (01.02.05) :

View Reliability of Results Fluid, Gas and Plasma Mechanics

Reliability of the scientific provisions of the research in the specialty Dynamics, strength of machines, instruments and equipment (01.02.06) :

View the reliability of the results Dynamics, strength of machines, devices and equipment

Reliability of the scientific provisions of the study in the specialty Biomechanics (01. 02.08) :

View reliability of results Biomechanics

Reliability of the scientific provisions of the research in the specialty General History (07.00.03) :

View reliability of results General history

Reliability of the scientific provisions of the research in the specialty Archeology (07.00.06) :

See reliability of results Archeology

Reliability of the scientific provisions of the research in the specialty Ethnography, Ethnology and Anthropology (07.00.07) :

View reliability of results Ethnography, ethnology and anthropology

Reliability of the scientific provisions of the research in the specialty History of International Relations and Foreign Policy (07.00.15) :

View reliability of results History of international relations and foreign policy

Reliability of the scientific provisions of the research in the specialty Mathematical and instrumental methods of economics (08. 00.13) :

View the reliability of the results Mathematical and instrumental methods of economics

Reliability of the scientific provisions of the research in the specialty Logic (09.00.07) :

View results validity Logic

Reliability of the scientific provisions of the research in the specialty Literature of the peoples of the Russian Federation (10.01.02) :

See the reliability of the results Literature of the peoples of the Russian Federation

Reliability of the scientific provisions of the research in the specialty Criminal procedure, forensic science; operational-search activity (12.00.09) :

View the reliability of the results Criminal procedure, forensics; operational-search activity

Reliability of the scientific provisions of the study in the specialty Correctional Pedagogy (13. 00.03) :

View the reliability of the results of the study Correctional Pedagogy

Reliability of the scientific provisions of the research in the specialty General psychology, personality psychology, history of psychology (19.00.01) :

See the reliability of the results General psychology, psychology of personality, history of psychology in full

Reliability of the scientific provisions of the research in the specialty Social Psychology (19.00.05) :

See the reliability of the results Social psychology in full

Reliability of the scientific provisions of the research in the specialty Legal Psychology (19.00.06) :

See the reliability of the results Legal psychology in full

Reliability of the scientific provisions of the study in the specialty Educational Psychology (19. 00.07) :

See the reliability of the results Educational psychology in full

Reliability of the scientific provisions of the study in the specialty Correctional psychology (19.00.10) :

See the reliability of the results Correctional psychology in full
Reliability of the scientific provisions of the research in the specialty Developmental Psychology, Acmeology (19.00.13) :

See the reliability of the results Developmental psychology, acmeology in full
Reliability of the scientific provisions of the research in the specialty Political institutions, processes and technologies (23.00.02) :

View reliability of results Full political institutions, processes and technologies

Reliability of the scientific provisions of the research in the specialty Cartography (25. 00.33) :

View the reliability of the results of the survey Cartography

Reliability of the scientific provisions of the study in the specialty Geoecology (25.00.36) :

View the reliability of the results of the study Geoecology

Reliability of the scientific provisions of the study in the specialty Theology (26.00.01) :

View the reliability of the results of the study Theology

Reliability of the scientific provisions of the research in the specialty System analysis, management and information processing (05.13.01) :

View the reliability of the results of the study System analysis, management and processing of information

Reliability of the scientific provisions of the research in the specialty Automation and control of technological processes and production (05. 13.06) :

View the reliability of the results of the study Automation and control of technological processes and production

Reliability of the scientific provisions of the research in the specialty Management in social and economic systems (05.13.10) :

View the reliability of the results of the study Governance in social and economic systems

What is the reliability and validity of the study? — Dissertatus.ru

useful materials

What is the validity and validity of a study?

What is the reliability and validity of a study?
Methods for checking the degree of reliability of research results in the thesis
Analytical
Experimental
Practical confirmation
How to ensure the reliability and validity of the results of the study?

One of the conditions for access to further defense of a written dissertation is the reliability of the collected results in the work. A dissertation candidate who wishes to obtain a degree must do experiments taking into account the topic under study. It will be necessary to provide hard and real evidence that the results obtained in the course of laborious research on the problem in the field of psychology actually work in practice.

What is the credibility and validity of a study?

Sufficient fidelity is a set of selected evidence that can confirm the data collected during the study, the patterns of probability. They were collected during experimental work, which allows you to get the reliability that characterizes the presence of real evidence. It is formed from scientific data.

The degree of reliability is always directly proportional to psychometric properties, often depends on the chosen instruments that are used during the experiment, so they are always checked, which confirms the accuracy, correctness of the interpretation of the result. It is necessary to use modern methods of analysis, evidence that is widely used in practice.

Methods for checking the degree of reliability of research results in the dissertation

Reliability assessment is a close relationship between several aspects and the study of the work area. Statistical methods must be used. The data of opinion polls are considered, measuring tools are used, which makes it possible to interpret the collected results in terms of strictly designated assessments and statistics. It is necessary not only to prove, but also to substantiate, to form specific concepts, proposals for improvement. Only then it is possible to prove the significance of the theoretical conclusions made by the dissertator and indicated in the work.

The following methods are used to prove the reliability of scientific work:

A comprehensive and most importantly objective analysis of the work done with those publications that are devoted to the subject under study in psychology over the past years. It is necessary to study the data in time for a carefully conducted experiment, to compare with the indicators that collected data from a proven methodological apparatus. Such information must be indicated in two sections of the dissertation.
Verification. It will be necessary to carry out several works that have identical characteristics of the objects under study. All results must be compared with each other. If they match, then the validity of the experiment is proved. Recommendations can be given in the dissertation.

Most often, only 3 effective and evidence-based methods are used, which include confirmation by practice, experimental methods and analytical ones. There is a significant difference between them. They will help to prove the recorded results, to confirm the data.

Analytical

They are widely used in research based on mathematical models. Such methods will be required to describe the experiment.

Experimental

To confirm validity, a comparison of theory and practice must be made. The dissertation student will need to take into account such factors as the number of works, the reality of the conditions, the error of the tools.

Validation in practice

This method is based on finding matches between practice and theoretical results. The main emphasis will be placed on determining the ratios of the initial volume, the conditions for practical testing, and the final results.

If there is a low agreement between practice and theory, this means that the instruments are incompatible with the experiments performed. You will need to choose other conditions for the experiment. You can change the tools to get reliable information.

How to ensure the reliability and validity of the results of the study?

Validity, reliability of data in the course of the study are confirmed by additional criteria:

an objective account is taken of all factors that influence the tasks set by science and are interconnected, help to achieve a positive solution to the problem under discussion;
application of the output data collected during the experiment in mathematical disciplines - the use of proven and semi-natural models;
definition of restrictions, as initial data, with arguments and formulated specific tasks;
use of a proven apparatus;
combination of theory with all the experiment done;
selection of criteria that are planned to be applied when studying a topic.
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