Midterm 1 (102) Flashcards
(84 cards)
Scientific Method
A set of general procedures for gathering and interpreting data. Controlled observation and measurement that permits replication of results.
Goals of the scientific entreprise in psych include: - measurement and description of behaviour. - develop measurement techniques to make it possible to describe behaviour clearly and precisely.
Achieve higher goal of understanding behaviour by specifying its causes, achieved by experimentation.
Can specify how behaviours and variables are related or co-occur together so that at least we can predict when those behaviours will occur.
Theory
A system of interrelated ideas used to explain a set of observations.
Account for a large number of disparate facts.
Generates Testable hypothesis.
A theory must be testable, and has to be falsifiable.
Empirical Test
Hypothesis
A tentative statement about the relationship between two or more variables.
Derived from previous knowledge.
Ideally a cause and effect statement.
Steps in a scientific investigation
Formulate hypothesis - based on current knowledge.
Design the study - put hypothesis to empirical test, choose the research that will help you.
Collect the data - specify the procedures for making empirical observations and measurements.
Analyze data and evaluate hypothesis.
Communicate the results - allows to be replicated.
Experiments
Variables
Experiments are the capstone of the scientific method.
Cause and effect relationships
Dependent variable —> measured behaviour
Independent variable —> cause of the behaviour
Operational definitions of variables
Need to operationally define the variables or translate the general concepts from the hypothesis into a set of operations which can be used in the experiment.
- narrow and specific interpretations of the general concepts
- several studies will show similar results when the independent and dependent variables have been operationally defined differently
Experimental Group
Exposed to a particular value of the independent variable manipulated by experimenter
Control Group
Comparison group exposed to the naturally occurring or zero value of independent variable
Notes on Groups
Characteristics of the experimental group must equal those of the control group.
When two groups are alike in all respects except for the variation created by the manipulation of the independent variable then it follows that differences between the two groups on the dependent variable must be due to the manipulation of the independent variable.
Extraneous Variable
People differ along may dimensions.
Any variable other than independent variable that could influence dependent measure.
Possible extraneous variables between groups compromise cause and effect conclusions —> confounding.
When confounding occurs, you may no longer attribute changes in the dependent variable to your manipulation of the independent variable because the confounding variable could be causing those changes.
Random Assignment
Subjects must be randomly assigned to conditions; in this manner, the influence of many potential extraneous variables will be unsystematic and tend to even out across large groups dependent.
More on how to not have extraneous variables
In some experiments, some subject can participate in all conditions or groups:
- extraneous subject variables ruled out
- subjects serve as their own control group
- however, must now be careful about the order in which subjects participate in the various conditions, counterbalancing
Often manipulate more than one independent variable in an experiment.
Evaluate separate and joint effects of each independent variable.
Subject and experimenter expectations can influence the outcome
(placebo/double blind)
Placebo Effect - an effect or belief without an actual influence by the presumed causal agent
Double blind - both the participants and the experimenter are unaware of the specific treatment condition —> protects against placebo effects
Experimental Research
Advantages/Limitations
One or more variables are systematically manipulated and the effect of that manipulation on other variables is studied.
Advantages - Strict control of variables offers researchers the opportunity to draw conclusions about cause and effect relationships.
Limitations - Artificiality of lab may influence subject’s behaviour. Many variables cannot be controlled and manipulated.
Non-experimental Methods
Do not manipulate the independent variable.
No random Assignment.
Cause and effect conclusions are not permitted.
Often used to: - Initially describe behaviour for future research
- Evaluate behaviour that cannot be experimentally examined
- Establish the degree of relationship between different variables and behaviour
Naturalistic Observations
Formal Record of observed events in natural setting.
Accurate first hand behavioural information.
Objectivity of observer essential.
Researcher should be unobserved by the subject.
Difficult to observe unobtrusively and behaviour can change if known you are observed.
Case Studies
Detailed history and analysis of a single individual.
Often used when an individual demonstrate a rare disorder or particular syndrome.
Often examine a collection of case studies looking for consistencies.
Limited in that the findings can’t be generalised to a larger population.
Time consuming and observer bias may be a problem.
Surveys
Large number of participants complete a self report questionnaire.
Collect data about behaviour difficult to observe.
Large amount of data can be gathered quickly.
Subjects must answer questions honestly and accurately.
Correlational Research
Employs statistical methods to examine the relationship between 2 or more variables.
Allows for prediction of behaviour from knowledge of certain variables: - positive /
- negative \
- zero –
Correlation
Quantifies the strength of association between 2 variables. Range between -1.0 < 1.0 Positive X goes up Y goes up Negative X goes up Y goes down O --> Correlation = 0.0 Correlation not equal causation
Descriptive Statistics
Used to summarise behavioural observations.
Need some ways to compare measurements to test the hypothesis of the research.
Summarise the performance of both individuals and groups.
Central Tendency
Mean, Median, Mode
Central Tendency - representative scores
Mean - arithmetic average
- sensitive to extreme scores
Median - middle value of scores
- rank order your group of scores from lowest to highest and choose the middle score
Mode - most frequent score
Variability
Degree to which a group of scores are clustered or distributed.
Standard Deviation (SD)
Variability goes up, SD goes up
Variability goes down, SD goes down
Normal Distribution
Scores cluster around the mean in the form of a bell shaped curve.
