pyschology research methods

• alternative hypothesis is the hypothesis the researcher tests by conducting a study and collecting data which attempts to show the null hypothesis is not supported
• condition: an experiment is usually organised in two trials after which the performances of the participants are compared these are the conditions of the experiment
• dependent variable :the factor which will be measured in an experiment to see if changing the IV has had an effect
• experiment: a research method in which the researcher tries to control all variables other than the IV and DV this allows the researcher to identify a cause and effect between the IV and DV
• hypothesis:a testable statement about the relationship between the two variables the IV and the DV
• Independent variable:the factor which will be changed in an experiment to see if it affects the dependent variable.
• null hypothesis is a hypothesis that exists and states that no variables affect any other variables
• variable is a factor or thing that varies,it can change
• experimental design is how participants are used in the conditions of an experiment
• independent groups is where two or more groups of participants are used in an experiment each group takes part in one condition
• matched pairs is where people with similar qualities are grouped into pairs each member of the pair takes part in a different condition
• order effect is when a participant's performance in the second condition of an experiment is affected because they have already done the first condition.They may do better because of practise or worse because of tiredness.
• Participant variables is the differences between the people who take part in the study.These may affect the results of an experiment.
• repeated measures is where only one group of participants is used in an experiment this group takes part in both conditions
• strengths of independent groups are there are no order effects because people only take part in one condition,the same material can be used for the task in both conditions and participants cannot work out the aim of the study because they only take part in one condition.
• weaknesses of independent groups are there are different people(participant variables)in the two conditions so that may be why the results are different and you need more people for the study to get 10 in each group you need 20 people
• strengths of repeated measures are the people in both conditions are the same so there are no participant variables and you only need 10 people to get 20 results because each person produces 'two scores'
• weaknesses of repeated measures are there are order effects as people have to do two tasks,you may need two tasks and participants may work out the aim of the study because they take part in both conditions.
• strengths of matched pairs are participant variables are reduced,there are no order effects and often the same material can be used for the task in both conditions
• weaknesses of matched pairs are matching is difficult,time-consuming and not always successful and some participants variables are still present
• extraneous variable is a variable that is not the IV but might affect the DV if it is not controlled
• standardised procedures is a set order of carrying out a study that is applied to all participants when necessary
• instructions are the written or verbal information given to participants during an experiment
• the instructions are done in sections the first is briefing this is what is said/written to encourage a person to agree to participate.It contains ethical information about consent,anonymity,the right to withdraw
• second section of instructions is standardised instructions these are clear instructions about exactly what the participant will do in the experiment
• third section of instructions is debriefing this explains the study in detail so that each participant is absolutely sure of the aim of the study,that is,why they were dong what they were doing in the conditions.Ethical issues are addressed again,especially the opportunity for the participant to withdraw their data if they feel unhappy about their performance
• randomisation is using chance to provide an order for a procedure
• allocation to conditions is putting participants into the conditions of an experiment e.g. random allocation
• random allocation can be achieved if 20 participants were available for the study the experimenter can put 10 pieces of the letter 'A' in a bag then ten letters of 'b' in the bag and then each participant takes a letter out determining the condition they take part in.
• counterbalancing is an arrangement in which half of the participants in an experiment are given the conditions in one order (A then B)while the other half is given them in the opposite order(B then A).
• Ecological validity is the results of the investigation can be said to apply for real life behaviour they are an accurate account of behaviour in the real world
• A laboratory experiment is an experimental method that is carried out in controlled settings
• A field experimental method is in a setting in which the behaviour would normally occur.
• A natural experiment is one in which the IV is not under control of the researcher e.g an experiment looking at gender or age differences.
• A strength of a laboratory experiment is there's lot of control of EV's means it is easier to establish cause and effect,so the researcher can be sure the IV affected the DV.
• A strength of a laboratory experiment is the high levels of control and standardisation mean the experiment can be replicated and the results can be confirmed.
• A strength of a laboratory experiment is there is high objectivity because opportunities for bias are reduced in the standardised procedures.
• A weakness of a laboratory experiment is the settings can be artificial with unrealistic tasks,so there is a lack of ecological validity.
• A weakness of laboratory experiment is participants are aware they are in a study so their behaviour can be affected and the results may be misleading or lack validity.
• A strength of field experiments is the setting is natural with realistic so there is a high ecological validity.