AP psychology module 6-8

which of the following is an example of negative correlation?

A. People who spend more time exercising tend to weigh less

which of the following is used only in correlation studies?

D. Scatterplot

researchers have discovered that individuals with lower income levels report having fewer hours of total sleep therefore,

A. income and sleep levels are positively correlated

which of the following correlation coefficients represents the strongest relationship between two variables?

D. -.85

the purpose of random assignment is to

D. reduce potential confounding variables

which of the following is a measure of variation?

A. Range

which statistical measure of central tendency is most affected by extreme scores?

A. Mean

A researcher calculates statistical significance for her study and finds a 5 percent chance that results are due to chance. which of the following is an accurate interpretation of the following?

B. this is the minimum result typically considered statistically significant

descriptive statistics... , while inferential statistics... ,`

E. summarize data; determine if data can be generalized to other populations

in a normal distribution, what percentage of the scores in the distribution falls within one standard deviation on either side of the mean?

D. 68 percent

which of the following is more likely to be emphasized in individualist cultures than in collectivist cultures?

C. personal achievement

what must a researcher do to fulfill the ethical principle of informed consent?

B. allow participants to choose whether to take part

which ethical principle requires that at the end of the study participants be told about the true purpose of the research?

D. debriefing

which of the following beliefs would most likely be held by an individual in a collectivist culture?

B. children should be encouraged to develop harmonious relationships

correlation

a measure of the extent to which two variables change together, and thus of how well either variable predicts the other

correlation coefficient

a statistical index of the relationship between two variables (from -1.0 to + 1.0)

scatterplot

a graphed cluster of dots, each of which represents the values of two variables. the slope of the points suggest the direction of the relationship between the two variables. the amount of scatter suggests the strength of the correlation (little scatter indicates high correlation)

illusory correlation

the perception of a relationship where none exists

experiment

a research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependant variable) by RANDOM ASSIGNMENT of participants, the experimenter aims to control other relevant variables

experimental group

in an experiment, the group exposed to the treatment, that is, to one version of the independant variable

control group

in an experiment, the group not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment

random assignment

assigning particpants to experimental and control groups by chance, thus minimizing preexisiting differences between the different groups

double blind procedure

an experimental procedure in which both the research participants and the research staff are ignorant(blind) about whether the research participants have received the treatment or a placebo. commonly used in drug evaluation studies

placebo effect

experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, whcih the recepient assumes is an active agent

independent variable

the experimental factor that is manipulated; the variable whose effect is being studied

confounding variable

a factor other than the independant variable that might produce an effect in an experiment

dependent variable

the outcome factor; the variable that may change in response to manipulations of the independant variable

validity

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

descriptive statistics

numerical data used to measure and describe characteristics of groups. includes measures of central tendency and measures of variation

histogram

a bar graph depiciting a frequency distribution

mode

the most frequently occuring score(s) in a distribution

mean

the aritimetic average of a distribution, obtained by adding the scores and then dividing by the number of scores

median

the middle score in a distribution; half the scores are above it and half are below it

skewed distribution

a representation of scores that lack symmetry around their average value

range

the difference between the highest and lowest scores in a distribution

standard deviation

a computed measure of how much scores vary around the mean score

normal curve

a symmetrical, bell shaped curve that describes the distribution of many types of data; most scores fall near the mean( about 68 percent fall within one standard deviation of it) and fewer and fewer near the extremes

inferential statistics

numerical data that allow one to generalize- to infer from sample data the probability of something being true of a population

culture

the ending behaviors, ideas, attitudes, values, and traditions shared by a group of people and transmitted from one generation to the next

informed consent

an ethical principle that research participants be told enough to enable them to choose whether they wish to participate

debriefing

the postexperimental explanation of a study, including its purpose and any deceptions, to its participants