Experimental method involves manipulating an independent variable (IV) to affect the dependent variable (DV), which is then measured and stated in results
Experiments can be field, laboratory, quasi, or natural
Aims in research are general statements made by the researcher about what they plan to investigate
Hypotheses are precise statements that clearly state the relationship between the variables being investigated, and can be directional or non-directional
Independent variables are manipulated by the researcher to affect the dependent variable, which is then measured
Operationalisation refers to clearly defining variables in terms of how they are measured
Extraneous variables are variables that affect the dependent variable (DV) and do not vary systematically with the independent variable (IV)
Confounding variables are variables other than the IV that have an effect on the DV and change systematically with the IV
Demand characteristics are cues from the researcher or research situation that may influence participant behavior
Investigator effects refer to unwanted influences from the researcher's behavior on the measured results
Randomisation and standardisation are used to minimize the effects of extraneous or confounding variables in research
Sampling methods include opportunity sampling and random sampling
Opportunity sampling involves recruiting conveniently available participants, while random sampling gives all members of the population an equal chance of selection
Laboratory experiments offer high control but lowecologicalvalidity, while field experiments provide naturalbehaviors but may lack control over extraneous variables
Quasi experiments have controlled conditions but may lack random allocation of participants, affecting internal validity
Natural experiments deal with real-life issues but may lack replicability and generalizability due to the rarity of natural events
Random sampling:
All members of the population have equal chances of being selected
Each member is assigned a number, then a random number table, generator, or lottery method is used to choose a partner
No researcher bias as the researcher has no influence on who is picked
Time-consuming as it requires a list of population members (sampling frame) and contacting them
Volunteer bias:
Participants can refuse to take part, leading to an unrepresentative sample
Participants may not take the study seriously if motivated by factors like money
Systematic sampling:
A predetermined system selects every nth member from the sampling frame consistently
Avoids researcher bias and is usually fairly representative of the population
Not truly unbiased unless a random number generator is used to start the systematic sample
Stratified sampling:
Sample composition reflects varying proportions of people in specific subgroups (strata) within the population
No researcher bias as selection within each stratum is done randomly
Produces representative data due to proportional strata, enabling generalization
Volunteer sampling:
Involves self-selection where participants offer to take part
Quick access to willing participants but can lead to volunteer bias and affect generalizability
Experimental Design:
Independent groups design: participants perform in one condition of the independent variable (IV), eliminating order effects and demand characteristics
Experimental Design:
Repeated measures: the same participants take part in all conditions of the IV, eliminating participant variables but presenting order effects
Experimental Design:
Matched pairs: pairs of participants are matched on a variable affecting the dependent variable (DV), one member does one condition and the other does another, reducing order effects but requiring a large pool of potential participants
Pilot Studies:
Small-scale versions of investigations done before the real study to identify potential problems and modify procedures
Single-blind and Double-blind Procedures:
Single-blind: researchers do not inform participants if they receive a test or control treatment to avoid bias
Double-blind: neither participants nor the experimenter know who receives a treatment to prevent bias
Observational Techniques:
Naturalistic observation: watching and recording behavior in a natural setting for high ecological validity but can lead to awareness and replication difficulties
Observational Techniques:
Controlled observation: watching and recording behavior in a structured environment for more control over variables but low ecological validity
Observational Techniques:
Overt observation: participants are aware they are being watched, ethically acceptable but likely to record unnatural behavior
Observational Techniques:
Covert observation: participants are unaware they are being watched, recording natural behavior but raises ethical issues
Observational Techniques:
Participant observation: the researcher is part of the group being observed, providing insight but risking behavior changes
Observational Techniques:
Non-participant observation: the researcher observes from a distance, increasing objectivity but open to observer bias
Observational Designs:
Unstructured observation: continuous recording for richness of detail but higher risk of observer bias
Observational Designs:
Structured observation: quantifying observations using predetermined behaviors and sampling methods for systematic data collection but less depth of detail
Observational Designs:
Behavioral categories: breaking down target behaviors into observable components for precise observation and measurement
Observational Designs:
Inter observer reliability: checking the agreement among researchers conducting the study to ensure unbiased reports
Observational Designs:
Inter observer reliability score above 80% indicates high reliability
When forming a behavioral categories list, it's crucial to ensure behaviors don't overlap with other similar behaviors, and they should be clearly operationalized
Structured interviews involve different types of sampling methods:
Time sampling: records behavior within a pre-established timeframe, reducing the number of observations needed but may be unrepresentative
Event sampling: counts the number of times a specific behavior occurs, useful for infrequent behaviors but may overlook important details or have counting errors
Correlations are used to investigate associations between two variables, measured but not manipulated like in experiments