Lecture #3 -

Question 1

Population

Answer 1

• This refers to the entire group of possible observations that you’re interested in studying. It’s the broader set you want to learn something about.

Question 2

Sample

Answer 2

• A sample is a smaller subset taken from that population. It represents a portion of the population, and researchers gather data from this sample to make inferences about the larger population.

Question 3

Random Sample

Answer 3

• Every member of the population has an equal chance of being selected for the study.

Question 4

Convenience Sample

Answer 4

• A sample that is made up of participants who are easily available or accessible to the researcher.

Question 5

Volunteer Sample (Self-Selected Sample)

Answer 5

• Participants choose to be part of the study, rather than being randomly selected.

Question 6

WEIRD Samples

Answer 6

Western
○
Educated
○
Industrialized
○
Rich
○
Democratic
●
Concern: Many studies use WEIRD samples, which are not always representative of
the global population. This can limit the applicability of research findings to more
diverse groups.

Question 7

Replication

Answer 7

• Repeating studies over and over again.

Question 8

Constraints on Generality (COG) Statements

Answer 8

• A statement specifying the target population to which the study’s results should generalize.

Question 9

Anecdotal Evidence

Answer 9

• Relying on personal experiences or testimonials instead of scientific data.

Question 10

Confirmation Bias

Answer 10

• “…our usually unintentional tendency to pay attention to evidence that confirms what we already believe and to ignore evidence that would disconfirm our beliefs”

Question 11

Illusory Correlation

Answer 11

• “…the phenomenon of believing one sees an association between variables when no such association exists”

Question 12

Personal Probability

Answer 12

• “…a person’s own judgment about the likelihood that an event will occur”

Question 13

Probability

Answer 13

• “…the likelihood that a particular outcome – out of all possible outcomes will occur”

Question 14

Expected Relative-Frequency Probability

Answer 14

“…the likelihood of an event occurring, based on the actual outcome of many, many trials”

Question 15

Steps for Calculating Probability

Answer 15

1. Determine Total Number of Trials
2. Determine Successful Outcomes
3. Calculate Probability

Question 16

Probability

Answer 16

• Refers to the proportion we expect to find in the long run

Question 17

Proportion

Answer 17

• Calculated as the number of successes divided by the number of trials

Question 18

Percentage

Answer 18

• This is simply the proportion or probability multiplied by 100.

Question 19

Null Hypothesis (H0H0 )

Answer 19

• A statement suggesting there is no difference between populations, or the difference observed is in the opposite direction of what the researcher expects.

Question 20

Research (Alternative) Hypothesis (HaHa )

Answer 20

• A statement suggesting there is a difference, often in a specific direction, between populations.

Question 21

Control Group

Answer 21

• This group does not receive the treatment or intervention being tested.

Question 22

Experimental Group

Answer 22

• This group receives the treatment or intervention being studied.

Question 23

Reject the Null Hypothesis (H0H0 )

Answer 23

• When the data suggest a mean difference, we reject the idea that there is no
  mean difference.

Question 24

Fail to Reject the Null Hypothesis (H0H0 )

Answer 24

- When the data do not provide enough evidence to support a mean difference, we fail to reject the null hypothesis.

Question 25

Type I Error

Answer 25

- Rejecting the null hypothesis when it is actually true.

Question 26

Type II Error

Answer 26

- Failing to reject the null hypothesis when it is actually false.