Posted on: 28th Apr 2020

Understanding Internal Validity of Research

The internal validity of research is very crucial for determining the relationship between cause and effect.  In this article, our professionals are providing proper guidelines about how to measure and maintain the internal validity of the research.


What is internal validity in research?

Internal validity can be referred to as extend up to which results of research attribute to the independent variables. It is basically a technique to measure the effectiveness of research. Internal validity can also be defined as the procedure of analyzing the effects which are observed by a researcher in a study is true. It is basically a yes or no type of concept.

Internal validity in quantitative research is basically a truth about interferences related to the relationship between cause and effect.  It is mainly concerned with the way researchers perform a study.

Quick Support from Singapore Writers in Completing Research Paper

How to achieve the internal validity of research?

One of the best techniques for achieving the internal validity  is to include fewer confounding variables in your study. There are other many variables that can be helpful in relation to improving the internal validity of research are randomization. It includes randomly assigning participants to treatment and control groups.  It helps in ensuring there is not any systematic biasness between groups. You can achieve internal validity by clearly stating the effects which you have observed in the study were because of the manipulation of the independent variable.

If you are trying to improve the internal validity of research then you need o to consider the different aspects of research design? It is the tactics which will also help you in making a decision related to accept or reject the alternative hypothesis. The different factors which can help in improving the internal validity of research are:

a) Randomization

It includes randomly assigning participants to the control group and treatments.  It is also very essential for you to make sure that there is no bias in the selection of groups.

b) Random Selection

You need to be very much careful while making a selection of participants using a random sampling technique. After making a selection of participants you should make sure that they represent the entire population.

c) Blinding

It is very much essential for the researchers and participants to make them aware of the interventions they are receiving a is very much important in order to avoid knowledge biasness.

d) Experimental manipulation

This technique of improving the internal validity of research includes the manipulation of independent variables in a study.  For example, including  smoker in the cessation program, rather than just observing relationship without executing any intervention  ( that is an examination of the relationship between exercise and smoking behavior)

e) Study Protocol

It includes complying with a particular process for management of treatment so as not to introduce any influence of, for instance, doing things differently with a single group of people versus another group of people.

Hire a Writer to Write your Research Paper before Deadline

Techniques to measure internal validity

You can measure the internal validity  by making a comparison between responses in the questionnaire with objectives of measurements of events or situations. For example, you can measure the reported amount of smoking with the purpose of measuring the nicotine level in cigarettes.

Another best technique to measure the internal validity  is to properly analyze the number of confounding variables that you have in the experiment.   If you are able to provide an alternative explanation for your research findings that means your research is internally highly valid.  The Three criteria which you can utilize for measuring the internal validity of the study  are:

  • The cause preceded the influence in terms of time.
  • There are changes in both cause and effect.
  • You face difficulty in providing an alternative explanation of the relationship between cause and effect which you have observed.

Importance of internal validly in Research

Maintaining the high level of internal validity is very much important for proving that it is the independent variable in the study which is influencing the dependent variable. In simple words. It has great significance in relation to demonstrating the causality between different variables.  Internal validity  is important as it helps in demonstrating that the researcher has proof of the study which they have performed on a specific topic.

Factor influencing the internal validity of research

There are a number of things which can influence the internal research validity of research some threats to the internal validity of research are:

1. Regression to the mean

It means that subjects in an experiment that have a high score would move towards average.

2. Pre-testing subjects

It can lead to unexpected outcomes. In case logical reasoning is a dependent variable then Due to pre-testing participants will get a hint about research, there are chances that they might provide wrong answers.  It is the factor which has a significant influence on research results.  Researchers mainly use a pre-test for influencing the research results of the post-test.

3. Changing the instruments

Consistency in research methods is very much essential for maintaining high reliability. In case the researcher changes the technique or process during study such thing can have a significant influence on internal validity.

4. Participants leaving research

It is considered as the biggest threat to the internal research validity . Participating leaving out can be a threat for investigators performing experimental research which involves more than one group.

5. Failure in completing protocols

  • Unexpected changes

There might be a few factors which by bringing unexpected changes that can influence dependent variables.

  • Confounding factors

It is basically including unexpected variables that might influence the causal relationship which you have tested when performing research. For example a new management system company will implement in an organization that might help in improving the level of job satisfaction among employees.

  • Maturation

Time can have a significant effect on the dependent variable or job satisfaction of workers.


From the above article it has been found that the internal validity  is essential for maintaining the effectiveness of research. Another fact which has been discovered from above is that there is a number of factors such as unexpected changes, the threat of human error, etc which can influence the internal validity of the research.

Hire Research Paper Writing Services in Singapore Now

Author Bio:

Angela Wong

Hi Guys, Happy to help you in research paper writing. I am post graduate from SUSS and now involved in providing assistance to Singapore students for making research projects during masters and Phd scholars. You can consult me for marketing, management, finance, accounting or any kind of research paper writing query