Exam 3

Question 1

What are some threats of validity?

Answer 1

History: Unpredicatble/ external events may occur during the course of the experiment affecting DV
Maturation: Subject changes / grows during course of study
Testing: Subject reaction to testing (retesting) itself.
Instrumentation: Chages in measurement process
Statistical regression to the Mean: Natural return to the average ( extreme scores particularly vulnerable)
Selection Bias: Lack of randomization (sample and assigment ) the way subjects are choosen
Experimination Moraility: Attrituion
Ambiguous causal time order: the dependent variable actually caused the change in the stimulus

Question 2

What are some threats to construct validity?

Answer 2

Measurement issues. measure it improperly impacts findings and able to generalize.

Question 3

Threats to external validity?

Answer 3

How generalizable are my studies. The more controlled the experiment the greater the external validity.

Question 4

What is nonprobablitiy sampling?

Answer 4

Denies the researcher the use of statistical theory to estimate the probability of correct inferences

Question 5

Stratifying a population prior to drawing a sample

Answer 5

generally occurs when the variables used to stratify are known to be associated with the dependent variable

Question 6

The unit about which information is collected and that provides the basis of analysis is called a(n)

Answer 6

Element

Question 7

Every kth element in a list is chosen for inclusion in the sample in what sample ?

Answer 7

systmatic sampling

Question 8

The standard error tells us how closely the population parameter is clustered around a single sample statistic? yes or no

Answer 8

Yes

Question 9

he more heterogeneous the population, the more beneficial it is to use stratified sampling. ?

Answer 9

Yes