RESEARCH METHODS Flashcards
Types of experiments
Lab experiment
Description, Strengths, Weaknesess
-Conducted in highly controlled environments, and allows the researcher to manipulate one variable (IV) to see the effect on another variable (DV).
-strengths: High control over extraneous variables, more certain of cause and effect, replication possible
-weaknesses: Demand characteristics, artificial tasks given don’t relate to real life
Types of experiments
Field experiment
Description, Strengths, Weaknesess
-These occur in ‘real world’ settings. The IV is manipulated by the experimenter and as many other variables as possible are controlled
-strengths: High ecological validity, Fewer demand characteristics
-weaknesses: Low control over extraneous variables so causality is harder to establish
Types of experiments
Natural experiment
Description, Strengths, Weaknesses
-When the researcher takes advantage of a pre-existing IV. It’s called natural as the variable would have changed even if the experimenter was not interested.
-strengths: Provide opportunities for research that wouldn’t have taken place before for ethical reasons, High external validity (real life issues)
-weaknesses: Lack of control over extraneous variables, relicability not possible
Types of experiments
Quasi experiment
Description, Strengths, Weaknesses
-They have an IV that is based on an existing difference between people (e.g. age/gender). Ppts cannot be randomly assigned to conditions.
-strengths: High ecological validity
-weaknesses: Lack of control over environment and extraneous variables (low internal validity), Not relicable
Aim
A general statement of what the researcher intends to investigate; the purpose of the study
Hypothesis
A clear, precise testable statement that states the relashionship between the variables to be investigated
Types of hypotheses
Directional hypothesis
States the direction of difference between variables.
Uses the word “increase/decrease”. Used based on previous research
Types of hypotheses
Non-directional hypothesis
Does not state the direction of the difference between variables.
Uses the word “difference”, used if previous findings are limited/contradictory
Types of hypotheses
Null hypothesis
States “there will be no difference” between the conditions.
It states that any differences are purely due to chance
Experimental designs
Independent groups
Description, Strengths, Weaknesses
Different groups experience different conditions of an experiment.
-strengths: no order effects, fewer demand characteristics
-weaknesses: more ppts required, ppts not the same in terms of ppt variables
Experimental design
Repeated measures
Description, Strengths, Weaknesses
All ppts experience all conditions of an experiment
-strengths: ppt variables controlled, fewer subjects required(more economical)
-weaknesses: order effects, demand characteristics may be a problem as ppt does both conditions
Experimental designs
Matched pairs
Description, Strengths, Weaknesses
Ppts are paired together on a variable that may affect the DV. one member assigned to one condition and other completes the diff condition
-strengths: subject variables kept constant
-weaknesses: matching is time-consuming, can never be perfectly matched, more ppts required
Types of studies
Pilot study
A trial run of the actual investigation. Normally involves a few participants in order to check the procedure, instructions, questions and extraneous variables.
Types of studies
Single blind study
A procedure in which the ppts are not informed of the research aim or hypothesis to reduce demand characteristics
Types of studies
Double blind study
A procedure where neither the participants nor the experimenter know the precise aims of the study. This reduces investigator effects and demand characteristics.
VARIABLES
IV, DV, CV
Define
IV- The variable that is manipulated in an experiment
DV- The variable that is measured in an experiment
CV- Variables that are kept the same across conditions in an experiment
VARIABLES
Extraneous
define and examples
Any variable other than the IV that may have an affect on the DV if not controlled.
E.g. intelligence level, age, gender, lighting, noise, time of day
VARIABLES
Confounding
Define
Uncontrolled extraneous variables that negatively affect the results
Randomisation
The use of chance to control the effects of bias
Random allocation
Assuring ppts have equal chance of being in any condition of an experiment. Attempts to evenly distribute ppt characteristics across the condtions of an experiment
Order effects
When the order in which tasks are completed affect the study’s results, either through practice or boredom
Counterbalancing
Ensuring that each condition of an experiment occurs first, and second, in equal measure to reduce possible order effects
Standardisation
Using exactly the same procedures and instructions for all ppts in the experiment
Investigator effects
Any effect of the investigators behaviour on the research outcome (DV)
Demand characteristics
Any cue from the researcher or situation that may reveal the aim of the investigation to the ppts. This may lead to the ppt changing their behaviour
Observations
Observation
A (non-experimental) research method where an observer watches and records behaviours.
Observations
What are observational techniques?
Types of observations
(naturalistic & controlled, overt & covert, participant & non-participant)
Observations
Naturalistic
Define, Strenghts, Weaknesses
-Takes place in a setting or context where the behaviour would naturally occur, and all aspects of th environment are free to vary.
-strenghts: High ecological validity, High external validity
-weaknesses: Lack of control over extraneous variables, replication not possible, Low reliability
Observations
Controlled
Takes place in a more structured environment, where it is possible to manipulate variables an control extraneous variables.
-strengths: High relability, researchers can manipulate variables, replicability is easy
-weaknesses: Low ecological validity, restricted environment may overlook the context in which the behaviour typically occurs
Observations
Covert
Occurs when participants are not aware that they are being studied, and have not provided consent. The behaviour being observed must be PUBLIC.
-strengths: Removes participant reactivity, reduces demand characteristics, increases validity of data
-weaknesses: ethical concerns ( no right to withdraw as they arent aware of the study, privacy, no consent)
Observations
Overt
Occurs when participants are aware that they are being studied and have provided informed consent beforehand
-strengths: maintains ethical transparency, researchers can ask questions to get a richer understanding of the context
-weaknesses: demand characteristics, observer effect
Observations
Participant
Happens when the researcher joins the group/individual being observed an participates in their behaviour
-strenghts: High validity of findings, Data gathered is rich/detailed
-weaknesses: can lead to bias )researchers involvement may influence their observations and interpretations), ethical concerns
Observations
Non-participant
Happens when the researcher remains seperate from those they are studying, and records from a short distance.
-strengths: Greater objectivity, reduces bias
-weaknesses: observer might miss critical emotional context, observer bias can still be a factor
independent groups
different groups of ppts experience different conditions of an experiment
strengths- no order effects, reduced demand characteristics
weaknesses- more ppts required, ppts are not the same in terms of ppt variables
repeated measures
all ppts experience all conditions of an experiment
strengths- ppt variables are controlled, more economical as fewer ppts needed
weaknesses- order effects, demand characteristics
matched pairs
ppts are paired based on variables that may affect the DV. one ppt is assigned to one condition and the other ppt is assigned to another condition
strengths-
weaknesses- time consuming, more ppts required
Internal validity
how accurately a test/measuring instrument measures what it says it measures
External validity
Factors outside of the investigation, e.g. generalising to other settings, populations and eras
Ecological validity
The extent to which research findings can be generalised to other settings and situations
Temporal validity
Whether findings from a study, or concepts within a theory, hold true over time.
Population validity
Whether findings from one group studied, can be applied or generalised to a wider population.
Face validity
Whether a test, scale or measure matches its aims. This can be checked by an expert.
