research issues

• In any experiment, there will always be a number of unwanted

  factors that can potentially affect the relationship between the

  independent and dependent variables, spoiling or

  distorting the results in the process.
• Invariably, studies in psychology involve a trade-off between control

  and realism. The greatest control can be achieved in a laboratory.

  However, it is debatable to what

  extent findings from the

  laboratory can be generalised to

  other environments, especially

  the less controlled environments

  in which everyday life is lived.
• Some psychologists argue that we can

  only discover things about behaviour if we

  uncover cause-and-effect relationships in

  highly controlled laboratory experiments.

  Others argue that studies in the natural

  environment are the only real option for

  psychologists who are interested in how

  life is actually lived.
• The key to an experiment is that an independent

  variable (IV) is manipulated (changed) to see how

  this affects the dependent variable (DV). The only

  thing that should influence the DV is the IV. Any

  other variables that might potentially interfere with

  the IV should be controlled or removed.

  These additional, unwanted variables are called

  extraneous variables and, where possible, are

  identified at the start of the study by the researcher,

  who then takes steps to minimise their influence.
• Many extraneous variables are

  straightforward to control such as

  the age of the participants, the

  lighting in the lab, etc.

  These may 'muddy' the experimental

  water but do not affect (confound)

  the findings of the study. They may

  just make it harder to detect a result.
• Confounding variables do change systematically with

  the IV. Let us imagine in our energy drink study we have

  twenty participants in total and decide to use the first

  ten participants who arrive for the water condition. It

  happens that these first ten participants are some very

  shy, introverted individuals. Our next ten participants,

  for the Red Bull condition, are all quite extravert types,

  very loud and outgoing. An unfortunate coincidence

  you say but this coincidence means that we have ended up with a second unintended IV- personality.
• Extraneous variable;

  Any variable, other than the independent

  variable (IV), that may have an effect on the

  dependent variable (DV) if it is not controlled.

  EVs are essentially nuisance variables that do

  not vary systematically with the IV.

  Confounding variables;

  Any variable, other than the IV, that may have affected the

  DV so we cannot be sure of the true source of changes to the

  DV. Confounding variables vary systematically with the IV.
• Participants are not passive within

  experiments and are likely to be

  spending much of their time trying to

  make sense of the new situation they

  find themselves in. As such, participant

  reactivity is a significant extraneous

  variable in experimental research and

  one that is very difficult to control.
• In the research situation, participants will

  try to work out what is going on. Certain

  cues may help them interpret what is going

  on. These cues are the demand

  characteristics of the experimental

  situation and may help the participant to

  'second-guess' the experimenter's

  intentions as well as the aims of the study.
• Participants may also look for clues to tell them

  how they should behave in the experimental

  situation. They may act in a way that they think is

  expected and over perform to please the

  experimenter (the please-U effect'), or, they may

  deliberately under-perform to sabotage the results

  of the study (the 'screw-U effect'). Either way,

  participant behaviour is no longer natural which

  means their behaviour is not genuine (valid).
• Demand characteristics;

  Any cue from the researcher or

  from the research situation that

  may be interpreted by participants

  as revealing the purpose of the

  investigation. This may lead to a

  participant changing their behaviour

  within the research situation.
• An investigator effect refers to any unwanted influence of the

  investigator on the research outcome.

  It might also refer to any actions of the researcher that were related

  to the study's design, such as the selection of the participants, the

  materials, the instructions, etc.

  Leading questions, which are discussed in relation

  to eyewitness testimony, are a good example of

  the power of investigator effects.
• Investigator effects;

  Any effect of the investigator's

  behaviour (conscious or unconscious)

  on the research outcome (the DV).

  This may include everything from the

  design of the study to the selection of,

  and interaction with, participants

  during the research process.
• Randomisation

  In any investigation there are simple steps that

  the researcher can take to minimise the effect

  of extraneous variables on the outcome.

  One of these is the use of randomisation,

  which refers to the use of chance wherever

  possible to reduce the researcher's influence on

  the design of the investigation. In short, this is

  an attempt to control investigator effects.
• Randomisation;

  The use of chance in order

  to control for the effects of

  bias when designing

  materials and deciding the

  order of conditions.
• Standardisation

  As far as is possible within an investigation,

  all participants should be subject to the

  same environment, information and

  experience. To ensure this, all procedures

  are standardised, in other words there is a

  list of exactly what will be done in the study.

  This includes standardised instructions that

  are read to each participant.
• Standardisation;

  Using exactly the same

  formalised procedures

  and instructions for all

  participants in a

  research study.
• Mundane Realism

  The aim of any psychological study

  is to provide information about

  how people behave in 'real life’ -

  the everyday settings in which life

  is lived. If the set-up of a study is

  too artificial or contrived then the

  participants will not act as they

  would normally.
• Mundane Realism

  Many things affect the realism of a psychological study. The term

  mundane realism refers to how an experiment mirrors the real world.

  'Mundane' means 'of the world’ - commonplace, ordinary. So lack of

  mundane realism means something is not like everyday experience.
• Mundane realism;

  Refers to how a study mirrors the real

  world. The research environment is

  realistic to the degree to which

  experiences encountered in

  the research environment

  will occur in the real world.
• Generalisation

  The point of realism in

  psychological research is to be

  able to generalise the results

  beyond the particular unique

  research setting - in particular to

  be able to understand behaviour

  in everyday life (the 'real world').
• If the materials used in

  the study are

  contrived/unrealistic

  (such as film clips) then

  the behaviour observed

  may lack realism.
• If the environment in

  which a study is conducted

  is contrived, and especially

  if participants are aware

  they are being studied, the

  participants' behaviour

  may lack realism.
• Even if the environment and materials are 'natural’ or real (i.e. high realism) a study can still lack generalisability. For example, if all the participants in a study are American university students, it may not be

  reasonable to generalise the findings to the

  behaviour of all people because Americans (and

  students) have unique characteristics that may

  set them apart in some way from other people.
• Generalisation;

  Applying the findings of

  a particular study to the

  wider population.
• Validity is not about confirming your expectations. Validity can

  be separated into internal validity and external validity.

  Internal validity is about control

  (confounding and extraneous

  variables) and realism.

  External validity is about being able to

  generalise from research participants

  to other people and situations.
• The term validity refers to how true or legitimate something is as an

  explanation of behaviour. It involves the issues of control, realism and

  generalisability.
• Internal validity concerns what goes on inside a study. It is concerned

  with things such as:

  Whether the IV produced the change in the DV (or did

  something else affect the DV, such as a confounding

  variable?).

  Whether the researcher tested what they intended to test.

  For example, if you were investigating intelligence and

  used an IQ to determine intelligence. Is an IQ test really

  an accurate way of testing intelligence?

  Whether the study possessed (or lacked) mundane realism.
• To gain high internal validity

  researchers must design the

  research carefully,

  controlling confounding and

  extraneous variables, and

  ensuring that they are

  testing what they intended

  to test.
• External validity is affected by internal validity - you cannot

  generalise the results of a study that was low in internal

  validity because the results have no real meaning for the

  behaviour in question. External validity also concerns:

  Ecological validity

  Population validity

  Historical validity
• Ecological Validity

  The place where the research was

  conducted (ecological validity).

  It may not be appropriate to

  generalise from the research

  setting to other settings, most

  importantly to everyday life.
• Population Validity

  The people who are studied

  (population validity). If a

  research study involved just

  students or all men or only

  Americans, etc. then it may not

  be appropriate to generalise

  the findings to all people.
• Historical Validity

  The historical period (historical

  validity). If a study was conducted in

  the 1950s it may not be appropriate

  to generalise the findings to people

  today because many other factors

  affect behaviour now.
• Validity;

  Refers to whether an observed

  effect is a genuine one.

  Internal validity;

  The degree to which an observed effect was due to the experimental manipulation

  (IV) rather than other factors such as confounding or extraneous variables.

  External validity;

  The degree to which a research finding can be generalised: to other settings

  (ecological validity); to other groups of people (population validity); over time

  (historical validity).