The Scientific Process

• Aim – an aim is a general statement of what the researcher intends to investigate. It is the general purpose of the study.

  Hypothesis – this a clear and precise, testable statement that states what you think the outcome of the study will be.

  • Directional hypotheses – states the direction of the difference. The direction is usually based on previous research on this area.
  • Non-directional hypotheses – these state that there will be a difference but does not state the direction.
• Independent variable

  • An independent variable is the thing that the researcher changes or manipulates.

  Dependent variable

  • A dependent variable is the thing that the researcher records or measures.

  Operationalisation of variables

  • Clearly defining variable in terms of how they can be measured.
• Extraneous variables

  • Extraneous variables are anything, other than the independent variable, that could affect the dependent variable if they are not controlled.

  Confounding variables

  • Confounding variables are anything, other than the independent variable, that could affect the dependent variable so we cannot be sure of true source of the changes to the dependent variable. We cannot control confounding variables usually.
• Population

  • Population is all the people who are the focus of interest for a researcher. Sometimes this is called the target population (the group at which your research is aimed).

  Sample

  • This is the group of people who take part in a research investigation. These people are gathered from the target population and should be representative of the group they come from.
• Sampling technique

  • This is the method used to select your sample from the population.

  Bias

  • This is when certain groups from your target population are either under represented or overrepresented.

  Generalisation

  • This is the extent to which the findings of a study can be applied to the population which they represent.
• Random sample

  • All names of members of the target population are put into a list. These names are each given a number and a lottery method is used to select a sample of people to take part in your study.

  Strengths

  • More representative than methods which do not gather all the names of the target population.

  • Free from researcher bias.

  Weaknesses

  • Can be difficult and time consuming to conduct as gathering a list of all of the target population can be difficult to obtain.

  • May still be unrepresentative due to chance.

  • Some people selected may not wish to take part in the study.
• Systematic sample

  • A sample frame is produced where all the names of the members of the target population are organised into a list. Then every nth person is selected from the list.

  Strengths

  • It is fairly representative especially if the interval is also randomised.

  • It is free from researcher bias.

  Weaknesses

  • It can be difficult and time consuming to conduct as gathering a list of all of the target population can be difficult to obtain.

  • The sample may still be unrepresentative, although this is unlikely.

  • Some people selected may not wish to take part in the study.
• Stratified sample

  • The researcher first needs to identify different sub-groups and then work out the proportions of each group. A representative sample should then be selected from each sub-group to take part in the research.

  Strengths

  • Very representative of the population, therefore it is very generalisable.

  • Free from researcher bias.

  Weaknesses

  • Can be difficult and time consuming to conduct as gathering a list of the target population and identifying the proportions can be difficult.

  • The identified strata cannot reflect all the ways that people are different.
• Opportunity sample

  • This is when you use anybody who is available and willing to take part in your study. This may mean approaching people that are passing by.

  Strengths

  • It is quick and easy so therefore convenient.

  Weaknesses

  • The sample may not represent the target population as the sample is drawn from a very specific area.

  • Researcher bias can occur as the researcher has complete control over who is selected.
• Volunteer sample

  • This is also know as a self-selecting sample because people volunteer to take part in the study. They may respond to an advert in a newspaper or raise their hand when a researcher asks.

  Strengths

  • It is an easy method that requires minimal effort on the part of the researcher.

  Weaknesses

  • Asking people to volunteer often leads to a certain ‘type’ of person who is helpful so they may not accurately represent the population.
• Pilot studies are small scale trial runs of the actual investigation. They allow the researcher to identify and modify any errors or problems with the study.

  Pilot studies in experiments: Check instructions for clarity, check design for appropriateness, tasks for appropriateness.

  Pilot studies on self report methods: Check the questions are clear and understandable, check practicality (time).

  Pilot studies in observations: Check location for equipment, check behaviour categories for suitability.
• Independent groups

  Two separate groups of pps are used with each group taking part in a different condition.

  Strengths

  Order effects do not occur. Order effects can be practiced (where they perform better in one part of the experiment because they know what to expect) or boredom (where they perform worse in the second part of the experiment because they are bored).

  Weaknesses

  Can be effected by individual differences. This can be reduced through

  random allocation of pps to the 2 conditions.
• Repeated measures

  One group of pps is used with the same group taking part in both conditions.

  Strengths

  The experiment is not affected by individual differences between the pps.

  Weaknesses

  Order effects may occur. This can be reduced through counterbalancing (varying the order that people take part in the experiment).
• Matched pairs

  Two groups of pps are used but they are matched on a variable. One ppt from each pair takes part in condition A whilst the other takes part in condition B.

  Strengths

  No order effects. Less chance of the study being affected by individual differences.

  Weaknesses

  There still may be some affects from individual differences as pps can never be matched exactly. It is time consuming and costly.
• Random allocation- attempt to control the affect of individual differences in an independent groups design by ensuring all pps have an equal chance of being in each condition.

  Counterbalancing- attempt to control the affect of order effects by getting half pps to do the two conditions in one order and the other half of the pps to do the conditions in another order.

  Randomisation- the use of chance to reduce bias when creating the study.

  Standardisation- when we use the same procedure and instructions for all pps in a study. This makes it fair and replicable
• Observational Design

  Observations are a non-experimental method where researchers see what people do in different situations without having to ask them.

  Behavioural categories

  • This is when the target behaviour is broken down and defined in a way which makes it measurable.

  Event sampling

  • This involves counting the number of times a particular behaviour (event) occurs in a target individual or group.

  Time sampling

  • This involves recording behaviours within a pre-established time frame.
• Questionnaires are a self report method which have a pre-set list of questions to which a ppt responds.

  Closed questions have a fixed set of responses that can be given by the respondent.

  Strengths

  • It produces quantitative data which is easier to analyse.

  Weaknesses

  • There is a lack of depth and detail in the responses given.

  • The response a person wishes to give may not be there so they have to put the ‘best fit’.
• Open questions do not have a fixed range of answers and the respondent is free to answer any way they wish.

  Strengths

  • It produces qualitative data which is rich in depth and detail.

  Weaknesses

  • It may be difficult to analyse the data and draw comparisons.
• Interviews are face-to-face or over the phone interactions between the interviewer and the interviewee.

  Structured interviews are made up of a pre-determined set of questions that are asked in a fixed order.

  Strengths

  • Easy to replicate due to standardised format.

  Weaknesses

  • Interviewers cannot deviate from the questions or ask the interviewee to elaborate on answers given.
• Unstructured interviews

  • Unstructured interviews have no set questions. There is a general topic which will be discussed but it is more like a conversation.

  Strengths

  • The interviewer can follow up points that are of interest so are more likely to gain real insight into the interviewee’s opinion.

  Weaknesses

  • It is difficult to analyse the data and draw firm conclusions.
• The British Psychology Society (BPS) has created a code of ethics that instructs psychologists about acceptable behaviour when conducting research. It is based around 4 main principles:

  RESPECT

  COMPETENCY

  RESPONSIBILITY

  INTEGRITY
• Informed consent

  • Pps need to be made aware of the aims of the research and give their permission to take part.

  • Informed consent is dealt with by using a consent letter with all the information about the study on it, which the ppt signs.

  Deception

  • Pps should not be deceived. Deception is about deliberately withholding information or misleading people.

  • This is dealt with in the debrief, where pps are told the true aims of the study.
• Anonymity/Privacy

  • Pps have the right to control information about themselves.

  Right to Withdraw

  • Pps have the right to stop participating in the study at any point.

  Confidentiality

  • All pps have the right to have any personal information protected.
• Protection from Harm

  • Pps should be protected from physical and psychological harm at all times.

  • This should be dealt with in the planning of the research and also in the debrief. This is an opportunity to check the pps are not affected negatively by the study in any way.

  Debrief

  • Pps have the right to know more about the research after they have participated and given an opportunity to ask questions.

  • The debrief is also an opportunity to check no harm has come to the participant whilst taking part in the study.