Issues

• Ethics are a set of guidelines which psychologists carrying out research should follow. Psychologists should always consider the following.
• Consent; Have the subjects of the study made an informed consent to take part? Have the parents of child subjects given informed consent to the research procedures? Have payments been used to induce risk taking behaviour?
• Deception; Have the subjects been deceived? Have the procedures been approved by other psychologists?
• Debriefing; Have the subjects been effectively debriefed? Has any stress caused by the procedures been removed?
• Withdrawal from the investigation; Are the subjects clear that they can withdraw from the study at any time without penalty or scorn?
• Confidentiality; Participants in psychological research have the right to expect that information they provide will be treated confidentially.
• Protection of participants; Investigators must protect participants from physical and mental harm 
• Observational research; Unless the participants give the consent to being observed, observational research must only take place where those observed could normally be expected to be observed by strangers.
• Giving advice; Psychological advice must only be given if the psychologist is qualified in the area that the advice is requested in.
• Colleagues; Psychologists should take action if they believe that any of the above principles are being violated by a colleague.

This term refers to how well a study can be related to or reflects everyday, real life. Studies with high ecological validity can be generalised beyond the setting they were carried out in, whereas studies low in ecological validity cannot. 

• A snap shot study is a study carried out over a very short period of time such as hours and days. In comparison, a longitudinal study is carried out over a longer period of time such as weeks, months or years. A longitudinal approach is where a group of participants is followed up after a period of time.

• Snap shot studies are obviously quicker and cheaper to carry out than longitudinal approaches and rarely suffer from attrition. However, they only provide us with a 'snapshot' of human behaviour and experience and therefore are not so useful when investigating development.
• Longitudinal studies are often found in the area of developmental psychology because they are ways of studying change over time. The longitudinal approach may suffer from attrition which refers to the loss of participants from a study. Reasons for attrition might include participants no longer wanting to take part in the study, moving away or losing contact. When attrition occurs psychologists have to question the representativeness of the remaining sample.

It is important to recognise that longitudinal studies and snapshot studies represent an approach and not an actual method of collecting data.

Data that describes meaning and experiences are known as qualitative data. Data that focuses on numbers and frequencies are known as quantitative data.

• Quantitative data are those that focus on numbers and frequencies rather than on meaning and experience. Quantitative methods (e.g. experiments, questionnaires and psychometric tests) provide information that is easy to analyse statistically and is fairly reliable. Quantitative methods are associated with the scientific and experimental approach and are criticised for not providing an in depth description.

• Qualitative data are those which are concerned with describing meaning, rather than with drawing statistical inferences. What qualitative methods (e.g. case studies and interviews) lose on reliability they gain in terms of validity. They provide a more in depth and rich description.

• Quantitative and qualitative methods of collecting data have both come under considerable criticism. In modern research, most psychologists tend to adopt a combination of qualitative and quantitative approaches, which allow statistically reliable information obtained from numerical measurement to be backed up and enriched by information about the research participants' explanations.