Experimental hypothesis - predicts a change(a testable statement)
Null hypothesis - predicts no significant difference.
One tailed hypothesis - when a hypothesis predicts the direction of the results e.g women are better drivers than men.
Two tailed hypothesis - does not state a direction, but simply says that one factor affects another or there will be a difference between two groups but gives no detail to how they will differ, e.g there will be a difference in driving abilities of men and women.
Independent variable (IV) - the variable that is manipulated/changed by the experimenter.
Dependent variable (DV) - the variable that the experimenter measures.
Demand characteristics - when the experimenter gives away what they are looking for and the participants change their behaviour because of this.
Experimenter effects - the experimenter can effect results due to the influence of their own behaviour, personality traits, etc.
Ecological validity - how realistic/close it is to generalised natural behaviour.
Extraneous variable (confounding variable) - any variable that can affect or bias the results, e.g age, weather, intelligence, distractions.
Social desirability - A bias resulting from participants giving responses that they believe will make them look "good" rather than giving honest responses.
Order effects - such as learning, fatigue or boredom may become constant errors when one condition is done after another e.g a subject given the same test may do better due to practice.
Lab experiments are done in a controlled enviornment. The experimenter manipulates the IV to see the effects on the DV, whilst controlling extraneous variables.
- Highly controlled
- Can be replicated
- Can control confounding variables.
- Lacks ecological validity.
- Participants know they are being observed - may cause demand characteristics.
- Experimenter effects
Field experiments are conducted in normal/everyday enviornment, but they are still artificial/set up. The experimenter still manipulates the IV but in a real-life setting.
- Still establish cause and effect as controlled.
- Can be replicated (most of the time)
- Behaviour is more natural - higher ecological validity
- Less likely to have demand characteristics as more natural.
- Participants are (sometimes) unaware they are being tested so haven't given consent (ethics).
- Less control than a lab experiment - means more extraneous variables, experimenter effects
- May be more time consuming.
Uses an existing situation and record people's reactions. Uses pre-existing groups of people. Nothing gets manipulated (IV) so there is limited control.
- High ecological validity.
- Unmanipulated so natural.
- Investigates the effects of independent variables that may be unethical.
- Hard to identify what aspects of IV may have caused the effects on behaviour.
- No control.
Pilot Study and Counter Balancing
- Mini run through of the experiment
- Identifies flaws
- Spots unusal things.
- May save time and money.
- Not so reliable as it is a small amount.
- To try and eliminate order effects in an independent methods design - half take part in one condition first and vice versa.
Correlation - Non Experimental Methods(NEM)
- Shows a pattern/trend
- They don't cause one another - they have a link
- Usually shown on a graph.
Positive correlation - the extent to which high values on one variable are associated with high variables on another variable.
Negative correlation - the extent to which high values on one variable are associated with low values on another variable.
Questionnaire - (NEM)
Questions are sent out to lots of different people and then the information is gathered. When writing a questionnaire you should take into account the following things; relevant questions, clear language, all possible answers (large range), correct audience, short and simple, suitable order, no leading questions(leads to a specific answer), avoid emotionally charged questions.
Open questions - free to write
Closed questions - have to choose an answer from the ones provided.
- Can gather lots of information/collect lots of data
- could be cheap
- no training needed
- less social desirability.
Questionnaire Disadvantages - (NEM)
- Participants may lie
- May contain vague questions
- May have misleading questions and answers
- No follow up
- Amount returned low/few people stop.
- Intimidation(if stopped in street etc)
- May have social desirability (if stopped in street)
Interviews - (NEM)
Interviews can be a one on one chat(informal dicussion). They can include detailed questions. Usually face to face, but can be done other ways (over the phone etc). There are three types of interview ; Structured - questions already decided(set list). Semi-structured - some set questions and some spontaneous. Unstructured - not really any set questions(spontaneous).
- Experimenter can see reaction
- Participant knows the topic(most of the time)
- Can have a follow up
- Convienient(people are more willing as it is on their terms)
- Rich detailed answers
- Participants may find it harder to lie/its more honest.
Interview Disadvantages - (NEM)
- Intimidation/experimenter effects.
- Demand characteristics
- Confidence may mean that the participants cannot answer question properly(shyness)
- Training is needed to conduct an interview
- Set questions may not address topic.(structured interview)
- May get off topic(unstructured interview)
- Participants may lie (social desireability)
- Leading questions.
Case study - (NEM)
A case study of one person or a small group. Case studies can be on anything and are an indepth study. The experimenter is highly involved in the participants life they ; speak to family, friends, teachers, social workers etc, conduct observations and interviews, they look into the participants background.
- Can research things you might not normally be able to.
- Gather lots of information and detail.
- Longitudinal (takes place over a long period of time)
- Experimenter may become attached to the participant as they are so involved in their lives, this may make the results not objective (biased).
Observation - (NEM)
An obervation means watching people, usually in their own enviornment (natural). There are two types of observation ; disclosed observation - told about the observation, non-disclosed obervation - not told about the observation(unaware).
- Non-disclosed -natural so you are observing their real behaviour (no demand characteristics)
- Disclosed - may have social desirability, demand characteristics
- Non-disclosed - unethical as they dont know they are being observed
Participant Observation and Non Participant Observ
Participant observation is when the researcher joins the group(infiltrates the group) and researches from within. Non-participant obervation the experimenter is watching from the outside(not much detail but may be unbiased)
- Ecological validity
- Low demand characteristics
- Lots of data
- Problems recording data without going un-noticed
- May be biased.
- Unethical(if they dont know they are being observed from within).
- Little or no control
- Extraneous variables
Reliability and Validity
Reliability is consistency - method repeated should get same/similar results(consistent). More control over method means more reliable, you test for reliability by repeating.
Inter rater reliability - experimenters compare notes and see if they match.
Validity - are we measuring what we think we are measuring. Extraneous variables mess up validity. Example - ofstead visit schools to measure the quality of teaching but what they actually measure is the quality of artifical teaching.
External validity - where you are (natural enviornment)
Internal validity - what we use (measuring tools)
There are ethical guidelines which must be followed when conducting an experiment. These are;
Informed consent - particpants must give consent.
Deception - do not lie to participants, some degree of deception permitted. debreif at end to explain what actually happened.
Right to withdraw - participants can leave at any time and can withdraw their data.
Protection from harm - not allowed to physically or psychologically harm participants, they must leave the experiment the same as they came.
Confiedentiality - ensure everything is confidential, must protect the participants identity, information needs to be kept safe e.g locked in a cabinet.
Experimental designs - Repeated measures
Involves using the same subjects in each condition of the experiment.
- Subject variables (individual differences shown by every subject) which could become extraneous variables are kept constant between conditions.
- Better statistical tests can be used because of less variation between conditions.
- Fewer subjects are required, therefore more economical.
- Order effects such as learning, fatigue or boredom may become constant errors when one condition is done after the other, e.g a subject given the same test may do better due to practice.
- Demand characteristics may become a problem-as the subject does both conditions of the experiment, they may guess the aim of the study and act differently.
- Different test may be needed to get better results.
Independent Measures - Experimental Designs
An independent measures design involves using difference subjects in each condition of the experiment.
- Order effects such as learning, fatigue or boredom do not influence the second condition since the subject only participates in one condition.
- Demand characteristics are less of a problem as the subject onlt participates in one condition so they are naive to the test, and it is less likely they are going to guess the aim.
- The same test can be used
- Subject variables differ, which could become extraneous variables unless controlled.
- More subjects are required and is therefore less economical.
Matched Pairs - Experimental Designs
A matched pairs design involves using different but similar subjects in each condition. An effort is made to match the subjects in each condition in any important characteristics that might affect performance.
- Subject variables are kept more constant between conditions.
- Order effects do not occour since the subject only takes part in one condition.
- Demand charateristics are less of a problem as subjects only take part in one condition.
- The same test can be used.
- Subject variables can never be perfectly matched in every respect.
- Matching subjects is very time consuming and difficult.
- More subjects are requires and it is therefore less economical.
Qualitive and Quantitive
Qualitative - quality, description.
Quantitive - number(numerical), how much.
Anything that can generate a yes or no answer is QUANTITIVE.
Explain your answer would make it QUALITATIVE.