research methods- reliability Flashcards
define internal reliability
the extent to which a test or measure is consistent within itself e.g. the use of standardised instructions and procedures for
all participants.
if the tool is measuring the same thing
it should produce the same results on every occasion. if it changes we must check whether that thing is being measured has changed - and not the measuring tool
issues of reliability
Lack of operationalisation of the variables is a potential issue.
If you do not clearly state how you are defining and measuring your variables, this makes replication impossible and makes inter-rater reliability issues more likely (see below for details).
Order effects can occur in a repeated measures design. Whilst completing the second condition the participant can become practiced/better at the task the second time round, or they can underperform due to factors such as boredom.
A lack of standardised
procedures, inconsistency of measuring tools and an uncontrolled environment all jeopardise reliability.
define external reliability
the extent to which a test produces consistent
results over several occasions.
how can reliability issues be overcome ?
Increasing levels of control in a study raises reliability – using a standardized
procedure, instructions and scientific measuring equipment conducting the research in a laboratory environment helps to overcome most reliability issues.
The greater the level of control, the lower the risk of extraneous variables effecting
results.
Order effects can be combatted with counterbalancing. This involves splitting
the population/sample into two halves; the first half complete condition one
followed by condition two, the second half complete condition two followed
by condition one. This in effect negates the impact of order/practice effects, as
both conditions are affected equally, and increases internal reliability
define inter- observer reliability
the extent to which two observers must be reliable
what is inter- rater reliability
measured by correlating the observations of two or more observers
The test-retest method
is used to asses external reliability. a group of participants are given a test or questionire or interview once and then again sometime later( when they have had the chance to forget it)
* test must be given to same person on two separate occasions
dealing with issues of reliability in self-reports
low internal reliability- questions can be removed to see if the split-half test returns a high-reliability score
In the care of external reliability, it may be poorly written questions that are causing confusion and need to be rewritten - if interview has low reliability interviewer may need to be restrained in order to be more consistent
define inter- rater
rate of which two or more individuals agree on something
