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. Questionnaires usually produce more quantitative data that is easier to analyse but not rich in depth. Questionnaires are more easily carried out than interviews but are not taken as seriously. Pps may also respond to social desirability and demand characteristics and give answers they think the researcher wants.
• Open questions do not have a fixed range of answers and the respondent is free to answer any way they wish.

  Strengths

  Produces qualitative data = rich in depth and detail

  Weaknesses

  May be difficult to analyse and draw comparisons

  
  

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

  Strengths

  Quantitative data = easier to analyse.

  Weaknesses

  Lack of depth and detail in responses

  Response may not be there so they have to put the ‘best fit’
• 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.
• Peer review is the assessment of scientific work by others who are experts (peers) in the same field. This occurs before a piece of research can be published.
• The aims of peer review

  • To allocate research funding. It may be that peer review takes place to decide whether or not to fund a research project that has been proposed.

  • To validate the quality and relevance of research. The research is checked for quality and accuracy.

  • To suggest amendments or improvements. Minor changes may be suggested by the reviewer or the reviewer may conclude that the research is not appropriate and should not be published.
• Strengths

  • It ensures validity and accuracy of research

  Weaknesses

  • Because the process is anonymous to ensure objectivity, some reviewers may use it as an opportunity to criticise rival researchers.

  • Some research is more exciting or interesting than others. To increase circulation of their journal, reviewers may only select headline grabbing research.

  • The process may be used to suppress research which contradicts mainstream theories.
• Psychology and the economy refers to the implications research has on the economy. Are they a benefit or do they devalue our economic prosperity?

  Treatments for mental illness can have economic implications because absence from work and sick benefits cost the government a lot of money. Often absences are due to disorders such as depression. Therefore treating depression increases productivity, decreases absences and contributes positively to the economy.
• Reliability refers to how consistent the findings, or measuring device, are of a study. This can be assessed in a number of ways.

  Method 1: test-retest

  • To test if a measuring tool is reliable we simply use the same test or questionnaire and check if the results obtained are similar.

  • If the correlation between the two sets of results is +0.8 or greater, then we can say that the results are reliable.
• Method 2: inter-observer reliability

  • To test if an observation is reliable we use more than one observer and then compare their results to see if they are the same or similar.

  Inter-rater reliability

  • In the same way we would use two observers in an observation we can also use two researchers to independently conduct content analysis.

  Inter-interviewer reliability

  • If the same interview is conducted by different interviewers this can be used to check the reliability of interviews.
• Validity refers to the extent to which an observed effect is real.

  Internal validity

  • Internal validity refers to whether the effects observed in an experiment are due to the manipulation of the independent variable or another factor.

  • One threat to internal validity could be demand characteristics.
• External validity

  • External validity refers to how much we can generalise the results of the study to other setting, populations or eras.

  • Ecological validity concerns generalising results from one setting to another, particularly everyday life. If a task does not represent everyday life it is said to be low in mundane realism.

  Temporal validity

  • Temporal validity refers to whether findings from a study, or concept within a theory, hold true over time.
• Assessment of validity:

  • Face validity is a way of checking the validity of a test by ‘eyeballing’ the measuring instrument or passing it on to an expert to check. Does it look like it is measuring what it is supposed to be measuring?

  • Concurrent validity is demonstrated when the results match, or are very close to, those obtained by another recognised and well-established test.
• Improving validity in experiments:

  • We could use a control group to check that any results are due to the manipulation of the IV.

  • We can also standardise procedures to minimise participant and investigator effects.

  • We can use single-blind procedures (where the participants are not made away of the aims of the study until after they have taken part) or double-blind procedures (where neither the participant or the person conducting the study knows the aims of the study until it is completed).
• Improving validity in questionnaires:

  • We can include a lie scale to check for social desirability bias.

  • We can also ensure all data is anonymous.

  Improving validity in observations:

  • We could conduct a covert observation to ensure the behaviour is more natural.

  Improving validity in qualitative methods:

  • You could demonstrate interpretive validity of your conclusions by seeing if your interpretation of the events matches those of the pps.

  • You could also use triangulation, which involves using a number of different sources as evidence.
• Features of Science

  Paradigms and paradigm shifts

  • A paradigm is a set of shared assumptions and agreed methods within a scientific discipline.

  • According to Kuhn, social sciences cannot be considered a science as they lack a universally shared paradigm.

  • A paradigm shift is when a significant change happens within a scientific discipline. This usually happens when there is too much contradictory evidence to ignore and a change is required.
• Theory construction and hypothesis testing

  • A theory is a set of general laws or principles that have the ability to explain events or behaviours.

  • Theory construction occurs through gathering evidence via direct observation.

  • It should be possible to make a clear and precise prediction on the basis of a theory. The role of hypothesis testing is to scientifically test those predictions.
• Falsifiability

  • Karl Popper argued that a key feature of scientific theory is falsifiability.

  • Scientific theories should be testable so it is possible to prove them false.

  • If a theory cannot be falsified it is not a true science.

  • The strongest theories are those which survive many attempts to falsify them.
• Replicability

  • If a scientific theory is to be trusted the findings must be shown to be repeatable across a number of different contexts and circumstances.

  • This allows us to see the extent to which we can generalise the findings.

  • Replicability requires researchers to report their investigations with as much precision and rigour as possible.
• Objectivity

  • Researchers need to remain objective and not allow their personal opinions or biases to affect the behaviour of participants or influence the results.

  • Methods with high control, such as experiments, are the most objective methods.
• Sections of a scientific report

  Abstract:

  • The first section of a journal article is an abstract. It is a short summary and includes all the major elements including aims, hypotheses, methods/procedures, results and conclusions. An abstract will allow the reader to decide if they want to read the whole report.
• Introduction:

  • The introduction is a literature review of the general area of investigation. It includes any theories, concepts and studies that are related to the current study.

  • The introduction follows the format of an upside-down triangle; starting broadly and becoming more specific until the aims and hypotheses are presented.