Scientific Methods Flashcards
Burden of Proof
The obligation to present evidence to support one’s claim
Extrasensory Perception
Supporters claim that some people sometimes acquire information without receiving any energy through any sense organ
Falsifiable
The theory is stated in such clear, precise terms that we can see what evidence would count against it
Hypothesis
A supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation
It is a clear predictive statement
Meta-Analysis
It combines the results of many studies as if they were all one huge study
Parsimony
When given a choice among explanations that seem to fit the facts, we prefer the one whose assumptions are fewer, simpler, or more consistent with other well-established theories
This principle is a conservative idea: we stick to ideas that work and try as hard as we can to avoid new assumptions
Replicable Results
Those that anyone can obtain, at least approximately, by following the same procedures
Theory
It is an explanation or model that fits many observations and makes accurate predictions
It is more than a guess
What are the steps in a study?
Hypothesis, method, results, interpretation
Why is there scepticism about extrasensory perception?
Psychologists carefully scrutinize claims of extrasensory perception because the evidence reported so far has been unreplicable and because the scientific approach includes a search for parsimonious explanations.
95% confidence interval
It is the range within which the true mean lies, with 95% certainty
Control group
A set of individuals treated in the same way as the experimental group except for the procedure that the experiment is designed to test
Correlation Coefficient
A mathematical estimate of the relationship between two variables (-1 to +1)
Demand Characteristics
Cues that tell participants what is expected of them and what the experimenter hopes to find
Dependent variable
The item that an experimenter measures to determine the outcome
Descriptive statistics
It is the mathematical summaries of results
Experimental group
Receives the treatment that an experiment is designed to test
Experimenter bias
The tendency of an experimenter to influence (unintentionally,as a rule) the participants based on his or her expectations
illusory correlation
An apparent relationship based on casual observations of unrelated or weakly related events
Independent variable
Item that the experiment changes or controls
Inferential statistics
They are statements about a large population based on inference from a small sample
Informed consent
A statement that participants have been told what to expect and that they agree to continue
Mean, median, mode
average, middle, most
Normal distribution
symmetrical frequency
Operational definition
It is a definition that specifies the operations (or procedures) used to produce or measure something, ordinarily a way to give it a numerical value → it just says how to measure something
p<0.5
it indicates that the probability that randomly generated results would resemble the observed results is less than 5%
Placebo
A pill with no known pharmacological effects
Random Assignment
The experimenter uses a change procedure, such as drawing names, to make sure that all participants have the same probability of being assigned to a given group
Scatter Plot
Each dot represents a given individual, with one measurement for that individual on the x-axis and another measurement on the y-axis
Statistically significant/reliable results
They are results that chance alone would be unlikely to produce
Why should experimenters overcome experimenter bias?
An experimenter’s expectations influence how the participants are treated. To ensure objectivity, researchers use blind experimenters who do not know what results are expected. In a double-blind study, neither the experimenter nor the participants know the researcher’s predictions.
Ethics of experimentation
Research on human participants should not proceed until the participants have given their informed consent. Psychologists try to minimise risk to their participants, but they sometimes face difficult ethical decisions.
single-blind study
researcher: aware
experimenter: unaware
participants: aware
OR
experimenter: aware
participants: unaware
Case study
detailed description of single individual; suitable for studying rare conditions
Naturalistic Observation
Description of behaviour under natural conditions
Survey
study of attitudes, belief, or behaviours based on answers to questions
correlation
description of the relationship between two variables that the investigator measures but does not control; determines whether two variables are closely related but does not address questions of cause and effect
Experiment
determination of the effect of a variable controlled by the investigator on some other variable that is measured; the only method that can inform us about cause and effect
what are the types of samples?
convenience, representative, random, cross-cultural
convenience sample
Individuals included: anyone who is available
Advantages: easiest to get
Disadvantages: results may not generalise to the whole population
representative sample
Individuals included: same percentage of male/female, white/black…as the whole population
Advantages: results are probably similar to the whole population
Disadvantages: sample may be representative in some ways but not others
random sample
Individuals included: everyone in population has same chance of being chosen
Advantages: best suited for generalising to the whole population
Disadvantages: difficult to get this kind of sample
cross-cultural
Individuals included: people from different cultures
Advantages: essential for studying many issues
Disadvantages: difficulties include language barriers and cooperation problems
