research methods Flashcards
lab experiment /true experiment
- In a “lab”
- Random allocation to condition (not random sampling, but close)
- Manipulate the IV
- Standardized - easy to replicate
- High internal validity
- Extraneous variables controlled
- Low ecological validity (artificial)
field experiment:
- Out in the field
- High ecological validity
- Lack of control - lower internal validity
- Manipulation of IV
- Participants allocated to different conditions, but often difficult to attain a random allocation
quasi experiment:
- Do not include random assignment to experimental conditions
- Participants are group based on pre-existing characteristics
natural experiment
- Involve pre-existing IV that are manipulated naturally, not by the researcher
○ Before and after Tv was introduced to regular Canada, before and after smoking ban in bars in Norway
○ Or between groups, schools which changed their starting time vs. Those who did not.
repeated measures (1 strength, 1 limitation)
- One sample receives each condition of an experiment
- STRENGTH: Participant variables are controlled, fewer participants - LIMITATION: order effects (practice effect), can be fixed by counter balancing, demand characteristics, confounding variable
independent samples
- The sample is randomly allocated to one condition:
- Half of the participants in one room (quiet)
- The other group in a room with music
- STRENGTH: order effects are controlled, less likely with demand charachteristics, same material for both groups
- LIMITATION: participant variability more likely, more participants
matched pair designs
- Participants are not randomly allocated to conditions. Instead, they are usually pre-tested with regard to the variable
- Pre-test to match participants on their level of memory skills, divide them and then do the experiment.
- STRENGTH: full range of abilities, lessen chances of participant variability
- LIMITATION: difficult to find appropriate matches,
Research designs: (3 types)
repeated measures
independent sample design
matched pairs designs
The IV is:
controlled by the researcher, independent variable
The DV is:
the dependent variable, something uncontrollable (like reactions)
to Operationalise
provides a clear and objective definition of variables
sampling techniques:
ways to gather participants for an experiment (Ex: snowball sampling)
Opportunity sampling
Participants are selected based on naturally occurring groups.
random sampling
Methods of selecting participants for a study where each member of the population has an equal chance of being selected. This can be done with a random number generator or by pulling names out of a hat.
self- selected sampling
Participants volunteer - usually in response to an advertisement in the local community or over the Internet.
snowball sampling
Participants recruit other participants for a study.
stratified sampling
The sample matches the make-up of the population. Participants from within various subgroups of the population are randomly selected.
the 6 ethics rules in studies:
informed consent, the use of deception, right to withdraw, no undue stress or harm to the participant, participant data must be anonymized, debriefing
informed consent
The participants knows and is informed about what is happening under the study if the use of deception is not used.
the use of deception
not informing the participant fully, but preferably avoid using deception, important with debriefing
right to withdraw
participants always have the right to withdraw or quit the experiments.
no undue stress or harm to the participant
the participants should leave the study in the same state that they entered, not physical or psychologically harmed.
participant data must be anonymised:
personal information about the participants should not be published.
debriefing
at the end of the study the participants needs to be briefed about what the goal was, and how their reactions/actions influenced the results of the study.
