# Two psychologists observe a student with attention problem to determine the percentage of time the student spends on a task in the classroom. They mark the student every ten seconds as either on the task or off the task. At the end of fifteen minutes, they compare their results.

Consider the following scenario:

Two psychologists observe a student with attention problem to determine the percentage of time the student spends on a task in the classroom. They mark the student every ten seconds as either on the task or off the task. At the end of fifteen minutes, they compare their results.

Based on your understanding of the above scenario, create a 2- to 3-page report in a Microsoft Word document answering the following:

• Explain the type of reliability that is being assessed by the two psychologists.
• Explain why it will be important for these two psychologists to address variance when they are trying to assess the reliability of their methodology.
• Explain why reliability is a property of an assessment score rather than a property of an instrument.
• Explain what will happen to the reliability of scores if:
• True scores are responsible for variability in observed scores?
• Random errors are responsible for variability in observed scores?

### Validity

Select any psychological trait such as:

• Extroversion
• Dependency
• Aggressiveness
• Agreeableness

Any trait is a fair game. Imagine that you have a colleague who created a new test to measure the psychological trait you choose. Because you are very interested in this particular psychological trait and thus, are interested in understanding whether your colleague’s test purports what it is touted to purport. Thus, you have decided to conduct a test to assess the validity of the instrument.