Scientific Processes Flashcards
what is the first step into conducting research?
aims
developing an aim and hypothesis
what is an aim?
aims
a general statement outlining the purpose of the investigation e.g. ‘to investigate effect of loud noise on recall’
what is an hypothesis?
hypothesis
a specific prediction about the outcome of the investigation - it will be tested in the investigation. e.g. ‘ loud noise will have a negative effect on recall’
how can a hypothesis be operationalized?
hypothesis
the nature of the variables and how they are to be measured must be clear in the hypothesis. e.g ‘exposure to 100 decibels of noise during a task will lead to poorer recall’
what is an experimental hypothesis?
hypothesis
a hypothesis for research adopting an experiment design
what is an alternative hypothesis?
hypothesis
a hypothesis for research adopting a non experimental deisgn e.g correlations, observation or self reporting studies.
what is a null hypothesis?
hypothesis
a hypothesis that predicts there will be no difference/relationship/association etc.
‘plant growth is not effected by light colour’
what are the two types of experimental/alternative hypotheses.
hypothesis
- directional
- non directional
what is a directional hypothesis?
hypothesis
a hypothesis that predicts a specific direction of outcome e.g ‘reaction time in sober ppts will be **greater than **that of drunk ppts’
usually has ‘greater than’ or ‘less than’
when would a directional hypothesis be useful?
hypothesis
when prior reserach indicates the results will go in one direction
what is a non-directional hypothesis?
hypothesis
a hypothesis that does not predict a specific direction of the results e.g ‘drinking alcohol will affect reaction time’
usually use ‘affect’ or ‘alter’
what is a sample?
sampling
the ppts selected to take part in research
what is the first step to sampling?
sampling
identifying the target population
what is a population?
sampling
the wider group of people identified as those that the findings of research should apply to
what the target population?
sampling
the particular group of interest to the research
how do we study the behaviour of the target population?
sampling
select a number of people from the population who are representative of everyone in the target pop.
what happens if the sample is not representative of the target population?
sampling
it is biased and we would not be able to generalise our findings to anyone other than the ppts in the study. e.g. all male sample, cannot be generalised to females
what else needs to be considered when choosing a sample?
sampling
sample size
what do researchers need to do to avoid a bias?
sampling
as large a sample size as possible and as representative a sample as possible
what are the 5 sampling techniques?
sampling techniques
- random
- stratified
- systematic
- opportunity
- volunteer
what is a random sample?
sampling techniques
a sample where all members of the target population have an equal chance to be selected
what is the logic behind a random sample?
sampling techniques
chance selection should mean no ppt characteristic is more likely than any other to appear, reducing likelihood of a bias
what are the ways to create a random sample?
sampling techniques
- computer selection
- lottery method
what is the computer selection method in random sampling?
sampling techniques
all potential ppts names are entered into a program that selects a specific number of entrants at random
what is the lottery selection method of random sampling?
sampling techniques
‘names in a hat’ : each ppt given a number that is entered into a lottery and a specific number are randomly selected
what are the strength and limitation of random sampling?
sampling techniques
S: investigator has no control so no investigator bias
L: still a small possibility of unrepresentative sample being chosen
what is a stratified sample?
sampling techniques
a sample where key characteristics of the target population are represented in the same proportion.
what is an example of stratified sampling using sexes?
sampling techniques
if target population is 60% male, 40% female, the sample must be made up of 60% male, 40% female as well.
how is a stratified sample selected once proportions are known?
sampling techniques
random sampling
what are the strengths and limitations of stratified sampling?
sampling techniques
S: avoids investigator bias
S: representative of population
L: if all key characteristics cannot be identified -> not representative
what is a systematic sample?
sampling techniques
a sample where ppts are mathematically chosen by dividing population by sample size and choosing every nth person from the list
how would ppts be chosen in a population of 200 and a desired sample size of 20?
sampling techniques
200/20 = 10
every 10th person from the list is selected
what is a strength and limitation of systematic sampling?
sampling techniques
S: the only input from investigator is sample size so no investigator bias
L: possibility that sample is not representative
what is a opportunity sample?
sampling techniques
a sample where ppts are selected due to convienient availability
e.g. a friend or someone passing by
what is a strength and limitation of opportunity sampling?
sampling techniques
S: less time consuming than other techniques
L: investugator may subconciously show bias so limits generalisability
what is a volunteer sample?
sampling techniques
a sample where ppts self select/volunteer themselves to be apart of the sample
how may a volunteer sample come about?
sampling techniques
adverts or posters
what is a strength and limitation of volunteer sampling?
sampling techniques
S: straight forward so less time consuming than other techniques
L: sample bias is likely as only certain types of people are motivated to volunteer so limits generalisability.
what is a pilot study?
pilot studies
a small, trial version of proposed studies to test the effectiveness and make improvements if necessary
what is the aim of a pilot study?
pilot studies
to identify potential issues early and rectified them before committing to the length and expense of a full investigation
what needs to happen in a pilot study regarding ppts?
pilot studies
the ppts must be typical of those taking part in the real study.
what can pilot studies allow researchers to do?
pilot studies
adjust design, procedure and analysis of findings in order to increase reliability and validity of final research.
what are the three types of experimental design?
experimental design
- independent groups
- repeated measures
- matched pairs
what is an independent groups design?
experimental design
an experimental design where each ppt only takes part in either the experimental conditon or the control one.
what type of data is produced by independent groups?
experimental design
unrelated data -> an individual’s data cannot be paired with another’s in the other condition
how are the ppts placed in which condition in independent groups?
experimental design
random allocation to balance out ppt (extraneous) variables across both conditions
example of an independent groups design:
experimental design
- 20 ppts divided into 2 groups by a coin toss
- 1 group is the control, group is the experimental
what are the strengths and limitations of independent groups design?
experimental design
S: no order effects, saves time and effort, demand characteristics reduced (can’t work out aim)
L: twice as many ppts required -> more money spent potentially, extraneous variables may affect results.
what is a repeated measures design?
experimental design
an experiemental design in which the same ppts complete both the experimental and control condition
what does repeated measures allow researchers to do?
experimental design
compare each participants score in both conditions
what type of data does repeated measures produce?
experimental design
related data -> an individual’s data from one condition can be paired with their’s from the the other condition
what are the strengths of using repeated measures?
experimental design
- uses fewer ppts so less time, effort and money spent.
- ppt (extraneous) variables) are not an issue as ppt does both conditions.
what is the limitations of using repeated measures?
experimental design
risk of:
- order effects
- demand characteristics
what are order effects?
experimental design
taking part in both conditions could lead to condition 1 influencing performance in condition 2. e.g boredom or fatigue
how can order effects be controlled?
control
counterbalancing
what is counterbalancing?
control
ABBA:
half the ppts do condition A then B first, whilst the other half do B then A. any order effects should be the same across conditions.
THIS WILL BE RANDOMLY ALLOCATED
why might ppts display demand characteristics in repeated measures?
experimental design
they may figure out the aim and alter their behaviour to fit what they believe the experimenter is looking for.
what is matched pairs design?
experimental design
an experimental design where ppts are assessed for a characteristic and paired up before being randomly allocated to either the control or experimental group.
what type of data does a matched pairs design produce?
experimental design
related data -> each ppt in one condition can be comapred with the ppt matched to them in the other
what are the strengths of using matched pairs?
experimental design
- reduced ppt (extraneous) variables
- no order effects as each ppt only does one condition
what are the limitations of using matched pairs?
experimental design
- need twice as many ppts -> time and effort
- very difficult to match people identically (similiar but not exactly the same) -> may only work on identical twins.
what is the independent variable?
variables
variable manipulated by the researcher.
what is the dependent variable?
variables
the variable that is being measured by the researcher
what are extraneous variables?
variables
an unwanted variable that can influence the measurement of the DV -> causing an error.
what are examples of extraneous variables?
variables
-demand characteritsics
-participant variables
-situational variables
-order effects
what are confounding variables?
variables
an uncontrollable variable that may influence the measurement of the DV.
what is meant by operationalisation of variables?
variables
clearly stating and defining the variable and how it will be measured in the experiment.
how may extraneous variables be controlled?
control
- situational: standardisation
- participant: randomisation + random allocation
-order effects: counterbalancing
what is standardisation?
control
ensuring that all ppts experience the procedure in the exact same way. any change in DV is due to IV
what is randomisation?
control
using chance to decide:
- the order in which ppts will experience each condition in repeated measures
- which material/stimulus is used at different levels of the IV
what is random allocation?
control
chance allocation of participants to conditions in an experiment e.g. toss a coin.
why is important that observations are designed carefully?
observational design
in order to reduce observer bias and remove the risk of subjectivity between observers and maximise objectivity.
**
what do researchers need to be aware of before starting an observation?
observational design
- what behaviour is being observed
- how exactly the behaviour is being measure
what are behavioural categories?
observational design
a list of all behaviours to be recorded during an observation
why is it important to have behavioural categories?
observational design
since different observers would have different interpretations as to what the behaviour may be (e.g aggression could be kicks or pokes). operationalises the DV.
what are the two ways you can record behaviours in an observation?
observational design
- event sampling
- time smapling
what is event sampling?
observational design
when you record on the behaviour checklist everytime the behaviour occurs/is displayed. (e.g. everytime someone kicks someone)
what are the strengths and limitations of event sampling?
observational design
S: gain a frequency count of behaviours
L: if behaviour is exhibited at same time. can be hard to record everything -> miss something.
what is time sampling?
observational design
when you record on the behaviour checklist what behaviours are present at prescribed intervals. (e.g every 10 seconds, record how many kids are kicking others)
what are the strengths and limitations of time sampling?
observational design
S: It can give an indication of how much time is spent on each behaviour.
L: some behaviours will be missed outside the intervals - observations may not be representative
what is a structured observation?
observational design
one where the observer records behaviours based on a predetermined checklist
- behaviour categories.
what are the strengths and limitations of structured observations.
S: easy to establish inter-rater reliability, easy to replicate, easy to record.
L: key behaviours may be missed as not part of checklist.
what is an unstructured observation?
observational design
one where the observer records everything they see during the observation time.
what are the strengths and limitations of unstructured observations?
observational design
S: researcher is taking into account all behaviours that are going -> increase validity
L: open to observer bias, behaviours may be missed = decrease in reliability
