Research Methods : Experimental Designs Flashcards
experimetnal design
how pt arranged
in relation to
investigating different experimental conditions
independent group design
2/ separate groups of pt
experience diff conditions
within the experiment
in independednt group if two levels of IV how many IV do pt experience
1
what is compared between the two groups in independent group design
performance
what is a repeated measure design
all particpants experiecne both conditions of the experiment
give e.g of how REPEATED MEASURES DESIGN would work - read the group design im asking for !
all partipants try condition a then allpt try condition b
what is compared in repeated measures and why
means of conditions
to see if theres difference
what os amtched pair design
pt paired based on variables relevant to experiment and then spit into different experimental conditions e.g iq
explain how pt matched together in memory study on the basis of IQ
matched on iqs as indicator of ability to recall info
top 2 iqs paired together
then perosn 1 experiences condition a
person 2 experiences confiiton b
and so on
what do matched pairs attempt to control
confounding variable of pt variables
what does a matched pair require if it is to be effective
pretest if matching is to be effective
how could you select matched pairs when observing hwo chattiness affected by coke
observe two chattiest people in the waiting room
its key : in an experiment the matched pair after being selected is then ran how ?
in same way as independent groups
-ve/biggest issue of a pt group (pv)
pt who … the … groups are not the … in terms of …. variables
Pt who OCCUPY the DIFFERENT groups are not the SAME in terms of PARTICIPANT variables
exaplin the biggest issue of IGD (PV)
biggest issue with independent group design is participants who occupy the different groups are not the …. in terms of ….
so if researcher finds a …. between the groups on the …. ….
this may be more to do with … .. than the effects of the …
therefore these differences may act as a … … reducing the …. of the …
biggest issue with IGD is pt who occupy the different groups are not the SAME in terms of PT VARIABLES
so if researcher finds A DIFFERENCE between group on the DV this may be more to do with the PV instead of effects of the IV
therfore these differences may act as a CONFOUNDING VARIABLE
reducing the VALIDITY of the FINDINGS
how can you deal with pt in diffreent groups not being equal in terms of PT variables
random allocation
Random Allocation
evenly …. the pt ….
across …. of the experiment
using … techniques
evenly distributing pt characteristics
across conditions of experiment
using random techniques
give an example of random allocation
paper with A/B written on them
placed in hat
researcher selects them one at a time to assign pt to groups
r -ve of independent group design (Point about RMD)
less economical than repeated measures
explain why IGD less economical than repeated measures
each pt contributes a .. .. only
therfore … times as many participants are …. to produce …. …. to that collected in a … … …
this therefore increases …. and … spent on recruiting pt
pt contributes SINGLE RESULT
2x many needed produce EQUIVALENT DATA that collected in RMD
therefore increases TIME/MONEY spent on recruting pt
+ves of IGD (0rder effect) short
prevents … ….
which is a problem in .. .. ..
as only … … condition
pt are … likely to … the aim which reduces …. ….
prevents order effect - a problem in RM
as only experience ONE condition
pt less likely to guess the aims which reduces DEMAND CHARACTERSITICS
biggest issue for RMD
order effects
eahc pt min 2 tasks
order of tasks may be significant
give e.g of when order effects happen in RMD
drinking coke in our chatty patty experiment
drinking coke may have continuing effects when drinking water
how do you deal with order efffects
counterbalancing
DEFINE counterbalancing
attempt to control order effect in RMD
Explain how CB works
ha;f pt do Condtion a-b
half do cnodition b-a
e.g p1 a-b
p2 b-a
p3 a-b
cool way to rember CB
ABBA
What’s key about CB as with random allocation in relation to PV
doesnt … the problem
but attemps to … out the …
Don’t remove / prevent problem
but attemps to balance out the effects
but attempts to balcnce out effects
LIMTATION OF repeated measure design
Order effect arise as repeating two taks can create …/….that may casue a …in performance on the second task
so it matter what … the tasks are in
alternativley pt performance may …. through effects of …
especially on a … … … - i.e pt may perform … on the second task
therfore order acts a … variable
which reduces the … of findings of experiment
LIMTATION OF repeated measure design
Order effect arise as repeating two taks can create BOREDOM/FATIGUE that may casue a DETERIORATION in performance on the second task
so it matter what ORDER the tasks are in
alternativley pt performance may IMPROVE through effects of PRACTICE
especially on a SKILL BASED TASK - i.e pt may perform BETTER on the second task
therfore order acts a CONFOUNDING variable
which reduces the VALIDITY of findings of experiment
LIMITATION OF RMD - demand charcatersitics
demand charactersitics are more of a … of RMD than … … …
as partcipants … all the … of the EXPERIMENT
so Its … likely they’ll …. the… of the STUDY
this means Participant’s … is no longer … therfore this becomes an …. that may affect the … VARIABLE and therefore reduce the … of the findings
demand charactersitics are more of a FEATURE of RMD than INDEPENDENT GROUP DESIGN
as partcipants EXPERIENCE all the CONDITINOS of the EXPERIMENT
so Its MORE likely they’ll WORK OUT the AIMS of the STUDY
this means Participant’s BEHAVIOUR is no longer NATURAL therfore this becomes and EXTRANEOUS VARIABLE that may affect the DEPENDENT VARIABLE and therefore reduce the VALIDITY of the findings
STRENGTH of using RMD participant variables
….. …. are controlled this is thereforre gives the research higher … as the same participants …… in both/all …..
PARTICIPANT VARIABLES are controlled this therfore gives the researche higher VALIDITY as the same particiants PARTICIPATE in both/all CONDITIONS
STRENGHT OF RMD - more economical
… participants are needed therfore less …./…. spent on recruiting them
more economical as
FEWER participiants are need therefore less TIME/MONEY spent on recruiting them
+ve of MPD (single condition)
…. only take part in a …. ….
so … effects and … charcteristics are less of a problem
meaning …. validity
PT only take part in a SINGLE CONDITION
so ORDER effects and DEMAND charcteristics are less of a problem
meaning HIGHER. validity of researh + compared to otther design
-ve of MPD(pv)
although tehres …. to reduce OV
participants are …. exactly ….
even identical …
becuase there will still be ….. ….. between them that may affect DV
Which can reduce validity of research - si this right
although ATTEMPTS to reduce PV
particpants are NEVER exactly MATCHED even idnetical TWINS
as there will still be IMPORTANT differences between them that may affect DV
-ve of MPD (OC/resources) less economical
matching may be …. …. and ….
particulaury is theres a …. …. required therfore its less …. than other experimental designs
matching may be TIME CONSUMING and .EXPENSIVE
particulaury is theres a PRE TEST required therfore
its less ECONOMICAL than other experimental designs
