D&A Unit 5 Exam Review

Sensitivity of measurement and alpha level also affect power

Lack of random assignment in a b/w-subjects design; lack of counterbalancing and control group in a w/in subject design

To control for confounds either hold an extraneous variable constant or systematically vary an extraneous variable

Must be able to rule out all other causal factors (e.g., selection bias, history effects, attrition)

Internal validity is about how well the experiment or study was conducted

When scores on the DV are so high that no differences between groups can be detected (task is too easy)

This level of the IV does not receive the treatment, intervention, or manipulation (may have more than 1 level here)

Pilot testing the DV enables the researcher to avoid floor and ceiling effects on the outcome variable

Existing characteristic of participants cannot be controlled/manipulated by the experimenter & might confound the study

What is Alpha (α) usually set at for hypothesis testing?

The placebo control group thinks they are in or receiving the experimental treatment, but they are not

Participants were to either write notes by hand or type notes; retention was analyzed via a quiz -- notes are the ...

The independent variable must have at least how many levels in an experimental design?

Why is it important to have adequate power in an experiment?

The factor being manipulated or controlled by the experimenter

When participants are not always assigned to different groups and are exposed to each level of the IV

Reject null when null is true; saying there is a relationship when there actually isn't (false +)

2 variables must be correlated w/ one another (e.g., studying and grades)

Size or magnitude of the effect in which the bigger the difference is b/w groups, the bigger the ______ size (Cohen's d)

In which design is internal validity the strongest?

As sample size increases, power decreases

Every participant has an equal chance of being placed into one of the IV groups to rule out individual differences

Behaviors that are the measured outcome of an experiment

Reject null when null is false; believe no differences exist b/w groups when there are differences (false -)

If you reject the null you have proved the alternative hypothesis

Allows us to reject the H₀ with some degree of confidence & refers to the probability that you will mistakenly reject H₀

Hypothesis testing determine the likelihood that the sample stat could be achieved if the hypothesis re: pop was true

Since a publication bias exists in academia, it is likely that we are missing lots of ____ effects in the literature

Researchers should operationally define the independent variable only

An extraneous variable like temperature might inadvertently affect participant performance on a test

The extent to which participants are involved or engaged in the study to measure true or real behavior

The chance of Type I error occurring is equal to alpha (α = .05 or 5% chance)

To be considered to have adequate power, what value should 1 - β be greater than or equal to?

The independent variable is also known as the outcome variable

Research hypothesis in which the outcome is predicted to occur in a certain direction

TypeII error happens when there is a true effect in the population but the researcher is not able to detect it in sample

The cause must precede the effect (e.g., drop a pen and it will fall)

A systematic research study in which some factors are varied and all other factors are held constant

3 criteria must be met before determining _______: Covariance, temporal precedence, and internal validity rule

Participants were to either write notes by hand or type notes; retention was analyzed via a quiz -- retention is the ...

This level of the IV receives the treatment, intervention, or manipulation (may have more than 1 level here)

Since a subject variable cannot be controlled for, causal conclusions, therefore, can be made

Neither systematic error nor random error threatens the internal validity of a study

β, used to determine the chance of Type II error occurring, is usually set to ...

Inferential statistics only describe the sample and conclusions do not extend to the population

What are two major factors that impact power?

1/2 the class is rndmly assigned to complete a group project while the rest complete individual projects; then reversed

In a between-subjects design, groups are exposed to the IV twice

Failing to reject the null means there is a relationship between or difference in the variables

A power analysis can help reduce _____ & estimate sample size based on effect size, α, & power b4 conducting the study

In a within-subjects design, what is used to avoid possible sequence effects (e.g., practice, fatigue, carry-over)

Inferential statistics are used in hypothesis testing in which we can have 2 outcomes: reject or fail to reject the null

The assumption that there are no differences between conditions, groups, or levels of the IV (assumed to be true)

Participants either write notes by hand or type notes; retention analyzed via a quiz. Levels are 1) handwrite 2) type

Used to determine causality

Results in biased scores b/c an extraneous variable influences all scores in the same direction

An initial, small-scale study to ensure the independent variable will have the intended effect

The probability of correctly rejecting the null when the null is false where it is equal to 1 - β

Comparison between 2+ groups; use random assignment to rule out dispositional factors (e.g., individual differences)

If alpha is set to .05, then there is less than a ____ chance that the outcome of the experiment happened by chance

Quasi-experiments look similar to experimental designs but often lack control and causal conclusions cannot be made

Extent to which changes in the DV were caused by changes or manipulations of the IV

An uncontrolled extraneous variable that influences the outcome in a systematic way

When scores on the DV are so low that no differences between groups can be detected (task is too hard)

Usually does not confound the study because the extraneous variable's avg influence is likely the same across levels

The extent to which the experiment resembles real life

A systematic way to test a hypothesis about a population using data measured from a sample

The experimental group is also known as the control group