research methods: experimental method Flashcards
What is the difference between a non-directional and a directional hypothesis?
directional - states the direction of difference or relationship (the way the study may go)
non-directional - doesn’t state the direction
When do you write a non-directional hypothesis and when a directional hypothesis?
directional - used when findings of previous research suggest a particular outcome
non-directional - used if findings of previous research is contradictory
What is the difference between the Independent variable and the dependent variable?
independent is manipulated, dependent is measured
What is meant by operationalisation’ of a hypothesis?
clearly defining variables n terms of how they are measured
Be able to write a directional and a non-directional hypothesis (operationalised)
directional- “ there will be a difference between…with more/less in the…”
non directional- “there will be a difference between…”
Describe these types of experiment: Lab, Field, Natural Quasi
lab- highly controlled experiment
field- IV manipulated in a more natural setting (everyday life)
natural- observing natural settings, experimenter notices conditions like an experiment and records findings
quasi- IV based on existing differences is manipulated (usually age, gender etc)
Give a strength and a limitation of the 4 different types
lab
+ high control over extraneous variables (easy replicable)
- low mundane realism
field
+ high mundane realism (no demand characteristics)
- hard to replicate due to ethical issues (cannot get consent)
natural
+ high external validity (mundane realism)
- hard to replicate as IV not controlled/manipulated
quasi
+ controlled conditions (same as lab)
- cannot randomly allocate participants due to extraneous variables
Describe the 3 experimental designs: Independent groups, repeated measures, matched pairs
independent groups - different participants used for 2 conditions of IV
repeated measures - same pp used for both conditions of IV
matched pairs - different pp used for 2 conditions but each group matched on similar characteristics relevant to study
Explain 2 strengths and 2 limitations of each experimental design
independent groups
+ demand characteristics less likely
- participant variables, effects DV not IV
matched pairs
+ demand characteristics and participant variables is reduced
- needs information to match, pre-testing may be needed which can be expensive and time consuming
repeated measures
+ less pp needed, no participant variables
- order effects likely and demand characteristics
Explain how random allocation is used to control for participant variables in an independent groups design
participants are allocated to conditions using random techniques so there is a equal mix across all groups
Explain how counterbalancing is used to control for order effects in a repeated measures design
participants sample is divided in half, one half completes the condition and the other half completes it in reverse order
Explain why task difficulty needs to be controlled in a repeated measures design
because the results could be effected by the difficulty of the tasks within groups instead of the conditions
Explain what is meant by Demand characteristics and suggest a way these can be controlled
participants guessing the study intention and acting how they think the observer will want them to, can be controlled by using deception and hiding the purpose of the study and use
Explain how investigator effects/researcher bias may affect a study and suggest a way these can be controlled
hen a researcher unintentionally, or unconsciously influences the outcome of any research they are conducting, can be controlled by using double blind studies
