issues of reliability and validity

Question 1

what is the definition of reliability?

Answer 1

refers to the consistency of the outcome or result found again and again. An example of this is whether a study is reliable. A study would be reliable is the study is replicable and the results are similar.

Question 2

what is the definition of validity?

Answer 2

refers to the extent to which a study measure what is intended to measure. An example is if a study is designed to measure aggression in a preschool child then it is important that the measures of aggression actually test the characteristic.

Question 3

what is the definition of internal validity?

Answer 3

this refers to whether the measures used in a test genuinely test what they are designed to test.

Question 4

what is the definition of external validity?

Answer 4

this refers to whether the find are generalisable to the target population. An example is Zimbardos et als prison study, are the results generalisable to the prison guards and the attitude of the prisoners in a prison?