research methods Flashcards
what is the aim
.General statement about purpose of experiment
.Aim leads to hypothesis
How do you write the aim
always begin with ‘to investigate’
What are the two types of variables
Independent variable (IV)
Dependent variable (DV)
Definition of the IV and the DV
IV= The one you manipulate/change
Dv= The one you measure
What are the conditions/levels of the IV
The IV has two levels
-Control condition (no item)
-Experimenter condition
Needed to make a comparison to get a conclusion
What is the hypothesis
scientific statement of prediction
How can you write a hypothesis
- IV and DV variables included
2.written as a statement
- needs to be operationalized
What are the two types of hypothesis
. null hypothesis
. Alternative hypothesis
what is a Null hypothesis
.States there will be no difference between finding before and after experiment with the variables
.These are made to be proven wrong
.Example= alcohol doesn’t affect driving ability
what is an alternative hypothesis
.Opposite to null hypothesis
.Predict there will be difference in findings before and after experiment
.Example=alcohol does affect driving
What are the two types of alternative hypothesis
.Directional (one tailed)
.Non-Directional (two tailed)
What is a directional hypothesis
.Higher/Lower
.Positive/Negative
Someone has done this experiment before
What is a non-directional hypothesis
Will say there is a difference but doesn’t say if it is higher or lower
what is operationalizing
making the variables clear and measurable
what is an extraneous variable
factor which affects the IV and is not intentionally included in the experiment (is extra to the IV)
why is it important to control extraneous variables
as they may affect the conclusion if not controlled
What is the difference between a extraneous variables and confounding variables
.extraneous variables can be controlled/removed
.confounding variables have already affected the experiments conclusion
what are the types of extraneous variables
- Experimenter variables
- Situational variables
- Participant variables
- Demand characteristics
what are experimenter variables (examples)
factors from the experimenter which affect the experiment
-Gender of the experimenter
-Tone of voice
-Body language
What are situational variables (examples)
outside influences on experiment E.G
-Heat
-Lighting
-Time of daylight
.Order of conditions (order effects)
what are participant variables (examples)
Differences between the participants
.Age
.Gender
.Intelligence
.Personality
What are demand characteristics (examples)
subjects pick up on the experiments objective and change behavior accordingly.
.Order of conditions
.Participants reactivity-please you/screw you
what is order effects
participants complete all conditions of the IV and may get bored/practice which makes the results inaccurate
what is order conditions and participant reactivity
Order of conditions- Doing both tasks can make them figure out what aim is
Participant Reactivity- Changing behavior because you are aware you are being watched (social desirability)
control experimenter extraneous variables
-Randomization- If reading from list randomize the list order so experimenter doesn’t have bias for words
-Double blind procedure- Neither experimenter/ participants know true aim of experiment
control situational extraneous variables
-Standardized procedure- everyone subjected to same conditions, experience and info.
-Can control order effects by doing counter balancing (ABBA)
What is ABBA
AB-50% Doing task A first then task B
BA-50% Doing task B first then task A
control participant extraneous variables
Sample- large/random selection to gain a representative sample.
Experimental design-matched pairs or repeated measure design.
Randomly allocated- all participants name/number. Alternate names/numbers going to different conditions of the IV
How do you control demand characteristics
Counter balance- ABBA
Placebo- hide stuff about experiment (whether they were a control or not)
Secret- Participants unaware of truth experiment (single blind procedure)
what is a laboratory experiment
.Done in controlled environment (scientific)
.IV is manipulated
What is a field experiment
.Done in natural environment
.IV is manipulated (still in natural environment)
.ppts may be unaware they are being observed
what is a natural experiment
.Done in natural environment
.IV not manipulated (unethical/impractical)
.IV is naturally occurring
Robber shot and witnesses asked to recall incident. IV is anxiety and DV is recall. Anxiety is naturally occurring
what is a Quasi experiment
.IV is not manipulated (already exists in a person)
e.g. age, gender intelligence
Split brain patients
Strengths of a laboratory experiment
.Highly controlled
.Reliability
.Participants aware of experiment
.Control over extraneous variables
weakness of a laboratory experiment
.Social desirability
.Decreased ecological validity and mundane realism
Strengths of a field experiment
.High in ecological validity
weaknesses of a field experiment
.Less control over extraneous variables
.Less ethical
.Less reliability
Strengths of a natural experiment
.Study real problems
.Research things which would otherwise be unethical/impractical to replicate
Strengths of a quasi experiment
.Study predetermined characteristics
Weaknesses of a natural and quasi experiment
(they share similar ones)
.No relationship established as IV is not manipulated
.Confounding variables cannot be control as no random allocation
.Lack cause and effect
Mundane realism?
extent to which procedures and material in experiment is similar to real life
Ecological validly?
Extent finding can be generalised to every day events
what is relaibility and validity
Validity is the truthfulness and the accuracy
Reliability is the consistency
