psych quiz 2

Correlation

A measure of the extent to which 2 factors vary together and how they predict each other

Positive correlation

when two factors move together, indicating a direct relationship between them.

negative correlation

when two factors move in opposite directions, indicating an inverse relationship between them.

Correlational coefficient

A numerical value that represent the strength of a relationship between 2 variables (-1.00 to +1.00)

Negative coefficient

no correlation

Positive coefficient

correlation

First thing to look for to determine the value of a correlational coefficient

It’s sign + or -

Second thing to look for to determine the value of a correlational coefficient

The absolute value (how far is it from zero), to measure the strength of the relationship

Correlation v.s causation

Correlation suggests a relationship but does not prove it

Illusionary correlation

percieving a relationship where none exists

Experiment

research method where an investigator manipulates one or more factors to observe the effect on behavior or mental processes

Experimental group

The group exposed to the treatment

Control group

The group NOT exposed to the treatment

Random assignment

Assigning participants to groups by chance, minimizing pre-existing differences between groups, only used in experimental method

Placebo effect

Experimental results caused by expectations alone

Random assignment v.s random sampling

sample decides who is studied and assignment decides who gets which treatment

Single-blind

participants are blind about whether they are receiving the treatment or placebo

Double-blind

Both participants and researchers are blind about whether treatment or placebo has been recieved

Independent variable

The factor that is manipulated, the variable whose effect is being studied

Dependent variable

The outcome or effect

Confounding variable

A factor other the the one being studied that could influence the results

Experimenter bias

Bias caused when researchers may unintentionally influence reults to confirm their own beliefs

Validity

The extent to which a test or experiment measures or predicts what it is supposed to

Qualitative research

narrative data, not numbers

Quantitative research

numerical data

lab setting benefits

allows psychologists to test theoretical principles in a simplified way

lab setting limitations

it is a simplified, unrealistic version of reality

informed consent

giving potential participants information about a study to allow them to decide if they want to participate

debriefing

post-experimental explanation of a study

confederate

an actor who pretends to be an ordinary participant

descriptive statistics

numerical data used to measure and describe characteristics of groups

Inferential statistics

used to analyze sample data so researchers can make broader conclusions about a larger target

histogram

a bar depicting a frequency distribution

Mean

average

median

middle score

mode

most frequently occurring score

percentile rank

percentage of scores that are lower than a given score

skewed distribution

representation of scores that lack symmetry around average

range

difference between highest and lowest scores in a distribution

standard deviation

computed measure of how much scores vary around average score

normal/bell curve

68%, 95%, 99%

meta-analysis

procedure for analyzing results of multiple studies to reach an overall conclusion

statistical significance

how likely it is that results occurred by chance or were actually real

effect size

the strength of the relationship between variables