Created by skmitchell
about 5 years ago


Question  Answer 
Hindsight Bias  The tendency to believe, after learning an outcome, that one would have foreseen it. 
Overconfidence  We tend to think we know more than we do. 
Hypothesis  A testable prediction, often implied by a theory. 
Scientific Method  A systematic, stepbystep procedure psychologists use when conducting research. By following these specific steps, psychologists seek cause and effect relationships which means that they can be certain. 
Operational Definition (Operation Definition)  Statement of your procedures; identifies the IV and DV, sampling and assignment. For example, human intelligence may be operationally defined as what an intelligence test measures. 
Case Study  An observation technique in which one person is studied in depth in the hope of revealing universal principles. EX: Phineas Gage 
Survey  Descriptive method; uses questionaires or interviews. 
Naturalistic Observation  Observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation. 
Correlation  Researchers observe or measure a relationship between variables. 
Correlation coefficient  A statistical index of the relationship between two things. (From 1 to +1). 
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 the scatter suggests the strength of the correlation (little scatter indicates high correlation). 
Illusory Correlation  A perception of a relationship where none exists. 
Ethical Principles for Animal Research  1.) Research must have a clear, scientific purpose. 2.) Provide humane living conditions for animals. 3.) Legally obtain animals. 4.) Least amount of suffering. 
Standard Deviation  Shows how far scores vary from the mean (average) score. 
689599.7 Rule  Means 68% of all scores fall within one standard deviation of the mean; approx. 95% of all scores fall within two standard deviations of the mean; 99.7% of all scores fall within three standard deviations of the mean. 
Normal Distribution  Forms a bellshaped or symmetrical curve (upside down u) with mean, mode, and median the same score; 2 sides are mirror images. Represents data about how most human traits are distributed through population. EX: SAT, IQ. 
Mode  The most frequently occurring score. 
Median  The middle score; score that divides a frequency distribution exactly in half; so that the same number of scored lie on each side. 
Mean  The average; sum of set of scores divided by the number of scores. 
Dependent Variable  What is being measured in an experiment; the research variable that "depends" on the independent variable. 
Crosssectional Study  Compares individuals at various ages at ONE POINT in time. (one and done) 
Longitudinal Study  Studies a single individual or a group over an extended period of time. Provide in depth information but can be expensive and timeconsuming. 
Random Assignment  Assigning participants to experimental and control groups by chance so that every individual has an equal chance of being put in any group or condition. Is not possible for studies dealing with differences between sexes or age groups. 
Zero Correlation  Indicates there is NO relationship between 2 variables. EX: hat size and shoe size. 
Negative Correlation  1.00 (closest to it); means 2 variables move in opposite directions. 
Positive Correlation  +1.00 (closest to it); means 2 variables move in the same direction. EX: Positive relationship between smoking and lung cancer. 
Participant Bias  Tendency for research participants to respond in a certain way because they know they are being observed. 
Research Bias  Tendency for researchers to look for evidence that supports their hypothesis and ignore contradictory evidence. 
Skewed Distribution  Distribution with most scores squeezed to one end, few scores stretch out like tail. Skew named for distribution of tail. Negatively skewedskewed to left. Positively skewedskewed to right. Mean pulled n direction of tail away from median; median measures centrality best. 
Reliability  Consistency or repeatability of results. Split halves reliability compares scores on half to other half. Test retest reliability compares scores on the same test taken at different times. interrater reliability compares scores by different scorer of the same test. 
Random Selection  Choosing of members of a population so that every individual has an equal chance of being chosen for a sample. 
QuasiExperiment  Measured of Dv (dependent variable) when random assignment to groups of a randomly selected sample is not possible. Often applies to studies involving sex or age of participants. Can suggest cause and effect. 
Quantitative Data  Information can be reported as numbers for ease of handling. Nominal scale uses numbers to name something, can be used to count cases. Ordinal scale can be ranked, ordered. Numbers cannot be average. 
Population  All of the individuals in the group to which the study applies. A sample is a subgroup of the population that participates in the study. 
Placebo  Psychical or psychological treatment given to the control group that resembles the treatment given to the experimental group, but contains no active ingredients. Placebo effectresponse to belief that the IV will have an effect, rather than the actual effect of the IV. 
Inferential Statisctics  Statistics used to interpret data and draw conclusions. Uses rules to evaluate probability that a correlation or difference between groups reflects a real relationship, not just chance (p) is the measure of real difference, p< 0.5 or p< 0.01 needed. 
Experimental Group  Group that your are experimenting on; receives the independent variable (IV). 
Experiment  Research method that involves manipulation of an independent variable (IV) under controlled conditions and measurement of its effects on a dependent variable (DV). Only method that can establish cause and effect between IV and DV. 
Ethical Guidelines for Human Research  1.) Informed consent. 2.) Voluntary participation. 3.) Debriefing. 4.) Confidentiality 
Descriptive Statistics  Numbers that summarize a set of research data from sample. Can be pictured as histogram or frequency polygon. 
Confounding Variables  Factors that cause differences between the experimental group and the control group other than the independent variable. EX: Experimenter bias (also called expectancy effect) occurs when a researcher's expectations about the outcome of a study influence the results. 
Central Tendency  Describes average of a distribution. Median is the middle score when data is ordered size. Mean is arithmetic average of scores. Mde is most frequent score, bimodal distribution has 2 most frequent scores, multimodal distribution has 3 or more. 