Chapter 2 : Methods Flashcards
Hindsight bias
The tendency to believe after learning about some outcome that you could have predicted it
Hypothesis
Prediction about what will happen under particular circumstances
Theory
A set of related propositions intended to describe some phenomenon or aspect of the world
Participant observation
Observational Research
Involves observing some phenomenon at a close range
Strength: become involved and gain a new understanding of the sample you are observing
Limitations: Observations can be misleading
Archival Research
Look at evidence found in archives (census reports, sports statistics, newspaper articles, and databases)
Surveys
Can be conducted using either interviews or written questionnaires
Population
Group you want to know about
Random samples
Are likely to capture the proportions of given types of people in the population as a whole
Convenience samples
can produce proportions that are severely skewed away from the actual proportions in the population as a whole
not random
Correlational research
Psychologists measure two or more variables and examine whether they are related
Correlation does not establish causation
Can point investigators to possible causal hypotheses about some aspect of the world
Experimental research
Enables investigators to make strong inferences about why a relationship exists or how different situations affect people’s behavior
establishes causality
requires an independent variable, which the scientist manipulates, and a dependent variable.
Limitation: ethically, some things can’t be studied with an experiment
Independent variable
presumed to the cause of some particular outcome
manipulated by scientists in an experiment
Dependent variable
what is being measured
it is hypothesized to be affected by the manipulation of the independent variable
Third variable
A variable, often unmeasured in correlational research, that can be the true explanation for the relationship between two other variables
Self-selection
In correlational research, the situation in which the participant, rather than the research, determines the participant’s level of each variable, thereby creating the problem that unknown other properties might be responsible for the observed relationship
Longitudinal study
Collecting measures at different points in time from the same participants
Experimental condition
the condition in which the person receives the “vaccine”
Control condition
the condition in which the person receives the placebo
Random assignment
Assigning participants in experimental research to different conditions randomly
Ensures that participants are as likely to be assigned to one condition as to another
Natural experiments
A naturally occurring event or phenomenon with somewhat different conditions that can be compared with almost as much rigor as conditions manipulated by the investigator in an experiment
External validity
Indication of how well the results of a study pertain to contexts outside the condition of the laboratory
Field Experiment
Takes place in the real world, usually with participants who are unaware that they are involved in a research study at all
One of the best ways to ensure external validity
Internal validity
The likelihood that only the manipulated variable- and no other external influence - could have produced the results.
is established by random assignment
An experiment lacks internal validity when there is a third variable that could plausibly account for any observed difference between the different conditions
Reliability
Refers to the degree to which a measure gives consistent results on repeated occasions or the degree to which two measuring instruments yield the same or very similar results
Measurement validity
Refers to the correlation between a measure and some outcome the measure is supposed to predict
Ex. IQ test validity is measured by correlating IQ scores with grades in school and with performance in jobs. If IQ scores predict behavior that requires intelligence, we can safely infer that the test is a valid measure of intelligence.
What are common threats to internal validity?
Selection bias
Differential attrition
Regression to the mean
Experimenter/rater bias
Expectancy/Hawthorne effects
Selection Bias
Assignment to conditions is not random but systematic, meaning that different kinds of people are in different conditions, and that may be the reason for the observed difference, not the manipulated variable itself.
effects internal validity
Differential attrition
If many more people “drop out” from one condition than another, the people who stay in the more taxing or upsetting condition are likely to be different from those in the other condition, thus under-mining random assignment
Regression to the mean
If people are in a study because they’re extreme on the variable of interest, they are likely to become less extreme even if nothing is done. Therefore, a “treatment” can seem effective even when it is of no value.
Experimenter/rater bias
If the dependent measure has an element of subjectivity and the rater knows the hypothesis or what condition the subject or object of judgment was in, the rater may make biased judgments
Expectancy/Hawthorne effects
Participants can be biased by their expectations about the purpose of the experiment and act in a way that confirms them.
Statistical significance
A measure of the probability that a given result could have occurred by chance alone
Replication
Involves the reproduction of research results by the original investigator or by someone else
Open science
Practices such as sharing data and research materials with anyone in the broader scientific community in an effort to increase the integrity and replicability of scientific research
Institutional Review Board (IRB)
A committee that examines research proposals and makes judgments about the ethical appropriateness of the research
Informed consent
A person’s signed agreement to participate in a procedure or research study after learning all of its relevant aspects
Deception research
Research in which the participants are misled about the purpose of the research or the meaning of somethings that is done to them
Debriefing
In preliminary versions of an experiment, asking participants directly if they understood the instructions, found the setup to be reasonable, and so on. After an experiment, debriefing is used to educate participants about the questions being studied.
Basic science (research)
Concerned with trying to understand some phenomenon in its own right.
Conducted with a view toward using the findings to build valid theories about the nature of some aspect of the world.
Applied science (research)
Science or research concerned with solving important real-world problems
Intervention
an effort to change a person’s behavior
