Unit 0 Test - Research Methods and Data Interpretation

psychology

psychology

the science of behavior and mental processes

critical thinking

thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions

hindsight bias (I-knew-it-all-along phenomenon)

the tendency to believe, after learning an outcome, that one would have foreseen it

peer reviewers

scientific experts who evaluate a research article’s theory, originality, and/or accuracy

theory

an explanation using an integrated set of principles that organizes and predicts observations

hypothesis

a testable prediction, often implied by a theory

falsifiable

possibility that an idea, hypothesis, or theory can be disproven

operational definition

a statement of the procedures (operations) used to define research variables. For example, intelligence may be operationally defined as what an intelligence test measures

replication

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding generalizes to other participants and circumstances

case study

an non-experimental technique in which one person is studied in depth in the hope of revealing universal principles

naturalistic observation

observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation

survey

a non-experimental technique for obtaining the self-reported attitudes or behaviors of people, usually by questioning a representative, random sample of them

social desirability bias

bias from people’s responding in ways they presume a researcher expects or wishes

self report bias

bias when people report their behavior inaccurately

sampling bias

flawed sampling process that produces an unrepresentative sample

random sample

a sample that fairly represents a population because each member has an equal chance of inclusion

population

all those in a group, from which samples may be drawn for a study

correlation

measure of the extent to which two factors vary together, and thus of how well either factor predicts the other

correlation coefficient

a statistical measure of the extent to which two factors vary together (from -1.00 to +1.00)

variable

anything that can vary and is feasible and ethical to measure

scatterplot

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

illusory correlation

the perception of a relationship where none or a stronger-than-actual exists

regression toward the mean

tendency for extreme or unusual scores pr events to fall back (regress) toward the average

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 dependent variable). By random assignment of participants the experimenter controls other relevant factors)

experimental group

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

control group

group not exposed to treatment in experiment; serves as a comparison to evaluate effect of treatment

random assignment

assigning participants to experimental and control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups

single-blind procedure

an experimental procedure in which the research participants are ignorant (blind) about whether they have received the treatment or a placebo

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

an inert substance or condition that may be administered instead of a presumed active agent, such as a drug, to see if it triggers the effects believed to characterize the active agent

placebo effect

any effect on behavior caused by expectations alone when a participant believes they received an active agent when in reality they got a placebo

independent variable

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

dependent variable

the experimental factor--in psychology, the behavior or mental process--that is being measured; the variable that may change in response to the manipulations of the independent variable

confounding variable

in an experiment, a factor other than the factor being studied that might influence a study’s results

experimenter bias

bias caused when researchers may unintentionally influence results to confirm their own beliefs

validity

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

quantitative research

research method that relies on quantifiable, numerical data

qualitative research

research method that relies on in depth, narrative data that are not translated into numbers

informed consent

giving potential participants enough information about a study to enable them to choose whether they wish to participate

Debrief

post-experimental explanation of a study (purpose, any deception, etc) to its participants

Descriptive statistics

numerical data used to measure and describe characteristics of groups (include measure of central tendency and measures of variation)

histogram

bar graph depicting a frequency distribution

mode

the most frequently occurring score in a distribution

mean

the arithmetic 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

range

the difference between the highest and lowest scores in a distribution

percentile rank

percentage of scores that are lower than a given score

skewed distribution

representation of scores that lack symmetry around their average value

standard deviation

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

normal curve

symmetrical, bell-shaped curve that describes the distribution of many types of data, most scores fall near mean (68% fall within one standard deviation of it) and less fall near the extremes

inferential statistics

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

meta analysis

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

statistical significance

• a statistical criterion for rejecting the assumption of no differences in a particular study

• statement of the probability that a result occurred by chance

effect size

strength of the relationship between two variables (larger the effect size, the more one variable can be explained by the other)