Research Issues

Research IssuesEcological Validity – degree of

which behaviour observed in study reflects everyday life. Takes into consideration:

◦Generalisability – the extent to which the findings can be generalised.

◦Representativeness (mundane realism) – The extent to which the study mirrors real life.

Task

Consider some of the following experiments that we have already studied. Write down whether you think they are high or low in ecological validity (consider both generalisability and representativeness) and give reasons to justify your answer.◦ Milgram’s 1963 study of obedience.◦ Hofling et al, 1966 Nurses Study◦ Rank and Jacobsen, 1977 Australian Nurses

study.◦ Mandel, 1998 Police Battalion 101.

Descriptive StatisticsMeasures of Central TendencyMeasures of DispersionVisual Display

Research IssuesEcological Validity – degree of

which behaviour observed in study reflects everyday life. Takes into consideration:

◦Generalisability – the extent to which the findings can be generalised.

◦Representativeness (mundane realism) – The extent to which the study mirrors real life.

Task

Consider some of the following experiments that we have already studied. Write down whether you think they are high or low in ecological validity (consider both generalisability and representativeness) and give reasons to justify your answer.◦ Milgram’s 1963 study of obedience.◦ Hofling et al, 1966 Nurses Study◦ Rank and Jacobsen, 1977 Australian Nurses

study.◦ Mandel, 1998 Police Battalion 101.

Descriptive StatisticsMeasures of Central TendencyMeasures of DispersionVisual Display

Measures of Central Tendency

Finding the average of raw data using mean, median or mode.

Mean – average (adding and dividing by n)

Median – middle value in ordered list

Mode – most common

Task

The class will be divided in to 5 groups. Each group needs to find the mean, median and mode of their topic.

1. No. of coloured paper clips.2. No. of coloured pins.3. No. of SG passes at Credit level.4. No. of hours slept last night.5. No. of siblings (including step and half

siblings). You must design this task yourself and

decide what is the best way to collect the data etc.

EvaluationMean – makes use of all data

collected but it can be misleading if there are extremes.

Median – not affected by extreme scores but not al scores are taken into account.

Mode – useful when in categories (ie coloured pins)

Measures of DispersionAnother way to describe the statistics is to

show how spread out the numbers are.

Range - difference between the highest number and the lowest. A set of numbers can have the same mean but a different range.

Find the range from yesterday’s tasks.Standard Deviation – requires a

mathematical calculator. Measures the spread of the data around the mean.

Visual DisplayEasy and quick way to interpret

results.Use your data from yesterday’s

task to create a bar chart which simply displays your relevant results.

Remember to label the x and y axis.

Quantitative and Qualitative Data

Quantitative Data – Numbers, raw scores, percentages, means (descriptive data)◦ Easier to analyse◦ Simplifies human behaviour

Qualitative Data – descriptions, words, pictures, meanings (interviews)◦ Represents the complexity of human

behaviour.◦ More difficult to analyse

SamplingWhen choosing participants

experimenters must choose a selection of the population which are representative of the target population. Types of sampling are:◦Opportunity◦Volunteer◦Random◦Systematic

Sampling

Opportunity - asking people off the street.◦Anyone who is available.

Inevitably biased

Volunteer – adverts ◦Offers access to variety of

participants. Volunteer bias – more highly

motivated

SamplingRandom – Randomly select

participants from the complete list of target population.◦Unbiased

Impossible to obtain complete list.

Systematic – selecting every nth member of the target population list.◦Often mistaken for random sampling –

random means taken from a hat/picked from a list without a systematic approach.

Ethical IssuesFinding a balance between the aims

of the experiment and the rights and wellbeing of the participants.

Issues to be considered are:◦Deception◦Informed consent◦The right to withdraw◦Protection from harm◦Confidentiality◦Privacy

DeceptionSometimes necessary to secure more

accurate behaviour.However – deception is unethical, it may

stop participants from giving informed consent (as they are not fully informed) and leads people to believe that psychologists are untrustworthy (not take part in an experiment again)

Ethical committee should approve such deception after weighing up pros and cons (subjective).

Debriefing (participants may still feel embarrassed).

Informed ConsentReveals true aim of the study and

may make results invalid.Participants need this information in

order to know whether they want to take part.

Presumptive consent – asking a group of similar people to the participants if they would agree to take part in the study – if they say yes you can presume that the participants would also agree (what people say and do are very different things).

Protection from physical and psychological harmSome of the bigger psychological

issues involve participant distress.

No harm (physical or psychological) should come to any participants and any risk of harm should be no greater than in the real world.

Difficult to predict the outcome of experiments eh Zimbardo’s Prison Experiment.

The Right to WithdrawMore difficult in observational field

experiments (Piliavin’s Altruism on a train study)

Everyone should have the option to quit, even with informed consent people may not be fully aware of what is going to happen.

Participants may not withdraw even if they want to through a feeling of obligation.

ConfidentialityIf findings are published it may

be difficult to promise complete confidentiality despite anonymity (St Helena), as some details may lead to participants being recognised.

Data Protection Act – confidentiality is a legal right.

Researchers shouldn’t record names.

PrivacyDifficult in field experiments.

(Middlemist et al, 1976, Pee study)

Everyone has a right to privacy.People should not be observed

without informed consent unless it is in a public place (what is a public place?)

Give retrospective consent and allowed to withhold data. (still acceptable? Someone has just watched you pee!)

Ethics Governing BodiesBritish Psychological Society

(BPS) and American Psychological Association (APA).

These bodies develop ethical guidelines (see handout) so as they are aware of what is acceptable and how to overcome any ethical issues.

Does this absolve the experimenter of responsibility?