The word reliability is used so often in our life. When we say that someone is reliable, we mean that that person is honest, predictable, consistent and stable. There can be many ways in which the reliability of the instrument can be improved as well as there are several ways in which the reliability of the instrument can be poorly affected. Following is a general list of the factors that can affect the reliability of the research instrument.
The questions in the instrument
The wording of the questions in your research instrument plays a vital role in determining the reliability of the research instrument. The test question should not be too easy so that anyone can answer them easily and without any thought. They should not be so difficult that no one can get a clue that what it’s all about. The wording of the questions should be chosen after considering the IQ level of the audience to which the instrument has to be submitted. The research questions in the research instrument should make the respondents think before answering them. This will also help ensure that the respondents provide true responses. Sometimes new researcher uses double-barrelled sentences and makes directional and leading questions, the respondents cannot give accurate responses if the questions have not been phrased correctly. Such biases are introduced by the researcher himself and if the researcher is not experienced in his field, he might not know that he is introducing bias in his research instrument.
The physical setting or the testing environment
The place where the test has to be conducted or submitted is very important in maintaining reliability in the research. It is important that the researcher controls extraneous factors while conducting the test. In social sciences and behavioral observations, there can be many factors that can ruin the research by introducing bias. There can be extraneous factors like noise, smoke, wind, cold or heat, bad odors etc. There can be several other factors that can act as an extraneous factor impacting the respondents responses to the questions. The external factors need to be controlled and the environment should be very comfortable and as natural as possible. There can be various research in which the noise, bad odors or too much cold are the independent factors that the researcher want to study, in such researches the researcher keep those factors affecting the testing environment. In short, the research environment should have to be very close to natural to make it reliable.
The respondents’ mood
The respondents mood is another important factor in obtaining reliable answers from them. The respondents should be provided a comfortable environment in order to avoid ruining their mood. The researcher himself can observe whether the respondent is in a good mood or not. A bad mood due to any factor can change their responses.
The nature of the interaction
In every step in submitting and conducting the test the researcher should ensure that he is developing a natural interaction with the respondent. In artificial setting, the researcher can take a good test but that test will not be reliable. The reliability of the instrument is highly dependent on how close to nature the researcher maintained the testing situation. The researcher should interact with the respondents in a natural manner, suitable to the demands of the test.
The homogeneity of the group
The audience to which the test is submitted by the researcher should have to be diverse. The diversity of the audience is another authentication that the testing is reliable. Homogenous audience cannot yield appropriate responses that can be applied to natural settings in day to day life.
The test-retest interval
To check the reliability of the research instrument the researcher often takes a test and then a retest. The interval between the test and the retest should have to be enough to make it more reliable.
The length of the test
The test submitted to the audience should have a length that can enable the researcher to analyze the responses easily. A small test might not be as reliable as a long test can be.