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56 terms

AP Barrons: Chapter 2: Methods

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Hindsight Bias
the tendency to believe, after learning an outcome, that one would have foreseen it. (Also known as the I-knew-it-all-along phenomenon)
Applied Research
scientific study that aims to solve practical problems
Basic Research
pure science that aims to increase the scientific knowledge base
Hypothesis
a proposal intended to explain certain facts or observations (expresses a relationship between two variables)
Dependent Variable
the outcome factor; the variable that may change in response to manipulations of the independent variable
Independent Variable
the experimental factor that is manipulated; the variable whose effect is being studied
Theory
aims to explain some phenomenon and allows researchers to generate testable hypotheses with the hope of collecting data that support the theory
Operational Definitions
clear, precise definitions and instructions about how to observe and measure concepts and variables
Valid
research is valid when it measures what the researcher set out to measure (accuracy)
Reliable
research is reliable when it can replicated (consistency)
Participants
individuals on which the research will be conducted
Sampling
the process by which participants are selected
Sample
the group of participants
Population
the mass from which the sample will be selected from; includes anyone or anything that could possibly be selected to be in the sample
Representative
the goal in selecting a sample, the sample must be a () of the population
Random Selection
every member of the population has an equal chance of being selected: increases the likelihood that the sample represents the population and that one can generalize the findings tot he larger population
Stratified sampling
process that allows a researcher to ensure that the sample represents the population on some criteria (example proportion group sizes)
Laboratory experiments
are conducted in a lab, a highly controlled environment (can control variables)
Field experiments
are conducted out in the world (more realistic)
Experiment
scientific method that shows a casual relationship (cause and effect)
Confounding variables
Is the difference between the experimental and control conditions
Assignment
is the process by which participants are put into a group, experimental or control
Random Assignment
means that each participant has an equal chance of being placed into any group (limits the effect of participant relevant confounding variables)
Participant-relevant confounding variables
the differences amongst participants; random assignment avoids this
Group average
differences between groups
Grouping matching
the group is equivalent on the same criteria (example: the same sex)
Situation-relevant confounding variables
the differences amongst participants' situations
Experimenter bias
is the unconscious tendency for researchers to treat members of the experimental and control groups differently to increase the chance of confirming their hypothesis
Double-blind procedure
occurs when neither the participants nor the researcher are able to affect the outcome of the research
Single blind
occurs when only the participants do not know to which group they have been assigned (strategy minimizes the effect of demand characteristics, response, or participant bias)
Demand characteristics
Cues about the purpose of the study
Response or subject bias
is the tendency for subjects to behave in certain ways (Example: social desirability)
Social desirability
the tendency to try to give politically correct answers
Experimental group
is the group that gets the treatment operationalized in the independent variable
Control Group
is the group that receives none of the independent variable
Hawthorne Effect
The effect that merely selecting a group of people on whom to experiment has been determine to affect the performance of that group
Placebo Effect
Method of control that allows researchers to separate the physiological effects of the drug from the psychological effects of people thinking they took the drug. (some people will receive the drug, others will receive placebos)
Counterbalancing
A procedure that uses participants as their own control group, Alternating the order in which participants perform in different conditions of an experiment. For example, group 1 does 'A' then 'B', group 2 does 'B' then 'A' this is to eliminate order effects.
Order effects
changes in a subjects performance resulting from the position in which a condition appears in an experiment
Correlation
expresses a relationship between two variables without ascribing cause
Positive correlation
means that the presence of one thing predicts the presence of the other
Negative correlation
means that the presence of one thing predicts the absence of the other
Ex post facto study
to seek to control all other aspects of the research process because the assignment of the independent variable has been predetermined
Survey method
involves asking people to fill out surveys, can be used to investigate whether there is a relationship between the two variables
Naturalistic observation
unobtrusive observation: goal is to get a realistic and rich picture of the participants' behavior
Case study method
used to get a full, detailed picture of one participant or a small group of participants
Descriptive statistics
describes a set of data
Frequency distribution
a distribution of observed frequencies of occurrence of the values of a variable
Frequency polygons
line graphs
histograms
bar graphs
central tendency
measures of it attempt to mark the center of a distribution
mean
add up all the scores in the distribution and divid by the number of scores, the average (measure of central tendency)
median
central score in the distribution, the middle number
mode
the number that occurs the most often, distribution may have more than one mode (a distribution is bimodal)
extreme scores (outliers)
the number that is out of place, often distorts the accuracy of the central tendency
Positively skewed
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