Reliability and validity

The two researchers compared their data to assess inter-observer reliability. This produced a correlation coefficient of +0.26

Briefly explain what a correlation coefficient of +0.26 means in terms of the reliability of the two researchers’ observations.

Outline one way in which the reliability of the two researchers could be improved.

The researcher was concerned about the reliability of the content analysis.

How might the researcher have assessed the reliability of the content analysis in this study?

The two researchers’ analyses of the diary extracts were found to be quite different.

Explain how the reliability of this content analysis could be improved.

Students self-reported their stress levels on a scale of 1–10.

Explain how this might have affected the validity of the data collected.

Explain how the reliability of the controlled observation could be assessed through inter-observer reliability.

Explain one reason why collecting quantitative data could reduce the validity of this study.

To assess the questionnaire’s validity, the researcher gave it to 30 participants and recorded the results. He then gave the same 30 participants an established questionnaire measuring locus of control. The researcher found a weak positive correlation between the two sets of results, suggesting that his questionnaire had low validity.

Explain how the validity of the researcher’s questionnaire could be improved.

Some critics have said that Pavlov’s studies may lack ecological validity.

What is meant by the term ecological validity?

Explain one limitation of assessing sleep quality using a rating scale of 1–10.

Table 1 shows the raw data for the observation.

After the observation, the students showed their raw data table to their psychology teacher. The teacher suggested that some of the behavioural categories in Table 1 were not valid examples of friendly behaviour.

Suggest two better examples of friendly behaviours that the students could have used in their observation. Explain why these might be more valid examples of friendly behaviour than the behaviours in Table 1.

The feedback from one of the schools was that recreational screen time affected pupils’ social interactions. The psychologist decided to investigate this further by using an observation of social interaction during playtime at the school.

Design the observation to investigate pupils’ social interaction in the playground.

In your answer you will be awarded credit for providing appropriate details of:

• type of observation, with justification

• choice of time sampling or event sampling, with justification

• dealing with one relevant ethical issue

• assessing reliability of the data through inter-observer reliability.

The student who carried out the study selected the two pictures. He decided himself which picture showed unkind behaviours and which picture showed kind behaviours.

Explain how the study could be improved by selecting the pictures another way.

Which of the following does reliability refer to?

Shade one circle only.

A The accuracy of the data

B The consistency of the data

C The levels of the data

D The validity of the data

The validity of the data was questioned when the researcher presented his results. The researcher explained that he chose to use the happiness questionnaire because it had high concurrent validity.

Explain what it means for a test to have high concurrent validity.

The questionnaire had high concurrent validity.

Validity was still a concern because the researcher knew which participants were in each experimental group.

Explain how this could have affected the validity of the study.

Using your answer to Question 25, suggest one way in which the researcher could modify the study to improve the internal validity of the study? Justify your answer.

The psychologist wanted to assess the reliability of the content analysis.

Explain how the reliability of the content analysis could be assessed.

The psychologist was concerned about the validity of the experiment.

Suggest one possible modification to the design of the experiment and explain how this might improve validity.

Design an observational study to investigate how people spend their time at the gym.

In your answer you will be awarded credit for providing appropriate details of:

type of observation with justification

operationalised behavioural categories

use of time and/or event sampling with justification

how reliability of data collection could be assessed.

Explain one problem with the method used to determine the number of miles walked in the week. Suggest an alternative measure that would overcome this problem.