Psychology Chapter on Correlation and Experiments

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Questions and Answers

What does a positive correlation indicate about two variables?

One variable decreases while the other increases.

Both variables move in the same direction. (correct)

One variable has no impact on the other.

The two variables are completely unrelated.

In an experiment, which term describes the group that does not receive the test variable?

Confounding variable group

Control group (correct)

Experimental group

Independent variable group

What is the primary purpose of random assignment in experimental research?

To manipulate the independent variable effectively.

To ensure that all participants have the same background.

To minimize preexisting differences between groups. (correct)

To influence the dependent variable outcomes.

What is an operational definition?

A specific measurement of an abstract variable. Signup and view all the answers

Which type of study ensures that both the participants and experimenters are unaware of the treatment groups?

Double-blind study Signup and view all the answers

What does sample bias refer to?

A failure to represent the larger population adequately. Signup and view all the answers

What is a placebo condition in research?

A condition where no treatment is given, but is believed by participants to be given. Signup and view all the answers

What does generalizability refer to in research findings?

The extent to which results can be applied to a larger population. Signup and view all the answers

What is the primary purpose of inferential statistics?

To make predictions and inferences about a population Signup and view all the answers

Which measure represents the middle value in a dataset?

Median Signup and view all the answers

Which scenario describes a negative skew?

Most values are high with a few exceptionally low values Signup and view all the answers

What does standard deviation measure in a dataset?

The amount of variation or dispersion Signup and view all the answers

What is a bimodal distribution characterized by?

Two distinct peaks in frequency Signup and view all the answers

What does statistical significance indicate in an experiment?

That results are likely true and not due to chance Signup and view all the answers

What role do Institutional Review Boards (IRB) play in research?

They ensure ethical standards are met in research involving human subjects Signup and view all the answers

What is the primary function of meta-analysis in research?

To combine results from multiple studies for comprehensive analysis Signup and view all the answers

Study Notes

Correlation

Correlation does not equal causation
Correlations predict
Correlation coefficient is an index of the relationship between two things from -1 to +1

Types of Correlation

Positive correlation- variables moving in the same direction
Negative correlation- variables moving in opposite directions

Experimental Method

One variable manipulated and the rest controlled
Independent variable is manipulated
Dependent variable is measured
Confounding variable influences independent and dependent variables, causing a spurious association
Operational definitions define variables in terms of measurement or manipulation

Participants in Experiments

Experimental group receives treatment
Control groups do not receive treatment
Random assignment minimizes preexisting differences between groups by assigning participants to groups by chance

Experimenter Bias

Researchers influence results to portray a desired outcome

Types of Blind Studies

Single-blind study- participants are unaware of group assignment, researchers are aware
Double-blind study- both participants and researchers are unaware of group assignment

Placebo Condition

Participants believe they are receiving treatment, but no treatment is administered

Sampling

Sample is a subset of a population
Representative sample accurately reflects population characteristics
Random sample gives each member an equal chance of inclusion
Sample bias occurs when some members of the population have a lower chance of inclusion

Generalizability

This is the extent to which results of a study can be applied to others

Statistics

Branch of math dealing with analyzing numerical data
Descriptive statistics summarize collected data
Inferential statistics allow for predictions and inferences about a population based on a sample

Measures of Central Tendency

Single value representing an entire distribution
Mean is the average
Median is the middle value
Mode is the most frequent value

Other Measures

Range is the difference between highest and lowest values
Normal curve is a bell-shaped curve representing frequencies concentrated around the mean
Regression to the mean is the tendency for extreme measurements to be closer to the average on subsequent measurements

Skew

Positive skew- more values on the lower side with a few high values
Negative skew- more values on the higher side with a few low values

Standard Deviation

Measure of variation or dispersion in a set of values

Percentile Rank

Percentage of scores equal to or lower than a given score

Bimodal Distribution

Distribution with two peaks or modes in frequency of occurrences

Statistical Significance

Results are probably true or just due to chance
Determines if the observed result would occur often or rarely when nothing special is happening

Effect Size

Measures the impact or effect of something
Shows how much a treatment helps compared to no treatment

Meta-Analysis

Statistical analysis combining results of multiple studies

Institutional Review Boards (IRB)

Review and approve research involving human subjects ensuring ethical standards are met

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Description

Explore the fundamental concepts of correlation and the experimental method in psychology. This quiz covers the distinctions between positive and negative correlations, the role of independent and dependent variables, and the impact of experimenter bias. Test your understanding of how researchers structure experiments to minimize bias and accurately interpret data.