A broad statement about what the researcher expects to find
A statement predicting what you expect to find, more precise than an aim.
A directional hypothesis predicts the direction of the results whereas a non-directional hypothesis just predicts a difference
Independant variable (IV) - what the researcher is changing
Dependant variable (DV) - what the researcher is measuring
Extraneous variables - factors that could influence the DV.
When participants guess what a study is about and change their behaviour accordingly
When the researcher inadvertently affects the outcome of a study by giving away what the expect to find and unintentionally influence the participants
A small scale version of a real study (a trial run) used to identify any problems and obtain feedback
Independant groups - Group 1: O O O Group 2: O O O
No problems with order effects or demand characteristics, but individual differences and more participants needed.
Repeated measures - Group 1 & 2: O O O
No individual differences & fewer participants needed, but order effects.
Matched pairs - Group 1: O-O Group 2: O-O Group 3: O-O
Combines the advantages of independant groups and repeated measures, but is difficult and time consuming and individual differences are a problem.
People most easily available
All members of the target population have an equal chance of being selected
people who choose to take part
Internal - the consistency of a measure within itself
External - the consistency of a procedure from one occasion to another
Split - half procedure: scores divided into two halves, scores on each half should correlate strongly if reliable
Equivalent forms: perform two tests, results should correlate strongly if reliable
Test - retest procedure: take the same test twice at different points, should correlate strongly if reliable
Simultaneous observations: two or more observers watch the same behavioural sequence
Replication: repeat using a standardised procedure
alter unreliable items
Improve internal reliability. Inter-observer: discuss and agree on operational definitions of behaviours, common practice sessions untill agreement is reached.
Internal - Face (whether a measure appears, at face value, to test what it claims to), content (whether the measure is appropriate for investigating the aims) and predictive (whether the measure can accurately forecast future concequences)
External - Ecological (other settings), historical (different periods in time) and population (other groups of people).
Face: consider the test/questionnaire/interview/experimental procedure they are using. Content: opinions of experts in that field. Predictive:assessed in relation to actual outcomes using a longitudinal design.
Using controls such as standardised instructions and blind or double-blind procedures, Alter the groups design. Standarsisation
Historical and population: take larger, more varied samples. Ecological: a balance needs to be found between introducing more controls for internal reliability and making the situation or task more realistic.
Informed consent - Participants should be told the true purpose of the study before they agree to take part. To overcome this - cost benefit analysis (weigh up the benefit to our understanding of human behaviour against the cost to the participant), Prior general consent (ask to sign general consent where they agree to the fact that they will not be fully informed) or Presumptive consent (get consent off a group of similar individuals).
Deception - Deception should be kept to a minimum. To overcome this - ethics comittee must approve the need for deception
Protection from harm - Participants must not be exposed to any physical or psychological harm greater than they would experience in every day life. To overcome this - anticipate the concequences. Stop the study if it is clear that harm is being caused
Right to withdraw - participants should be informed that they have the right to withdraw themselves or their contribution to the research at any point. To overcome this - make participants aware at the start of the study that they can withddraw at any point
Confidentiality - Researchers should keep participants' names confidential. To overcome this - do not record the names of the participants, use numbers or false names. Withhold any information that could lead to people working out the identity of participants
Privacy - Participants must not be observed unless in a place where they would ordinarily expect to be observed. To overcome this - only observe in a public space or gain retrospective consent (consent after the study)
Measures of central tendancy/dispersion
Mean - add together and divide by how many there is. Good because it uses all of the data, but bad because one rogue score can heavily influence it
Mode - most common. Good for knowing how often things happen, but bad because often a set of data does not have a most common value and sometimes it has lots of common values.
Median - the middle value. Good because it's not heavily influenced by rogue scores, but bad for using with small data sets.
Standard deviation -
Range - the difference between the highest and lowest values. Good because it takes extreme scores into consideration and is simple to calculate, but it tells us little about how spread out or clustered the data is
Levels of measurement
Nominal data - data that can be classified into categories, and if something is in one category it cannot be in another
Ordinal data - There is an order to the scores, in some sort of rank.
Interval data - Measuring something on a scale (time, temperature, weight and height)
Ratio data - same as interval but has an absolute zero point whereas interval has an arbitrary zero point (zero degrees temperature does not mean there is no temperature, but having zero pounds in your bank account would mean that you have no money)
Used for analysing transcripts of interviews, text, adverts, books, newspapers etc. The researcher creates a coding system and predetermined categories at the start of the study which is then applied consistently
Good because dreating a coding system allows different researchers to compare their data. If the findings are consistent then it indicates that the coding system is well designed.
Bad because the richness and complexity of the qualitative data is lost, it is reductionist.
The scientific process
Observation of subject matter, leading to the formulation of a theory. This is tested by hypothesis construction through empirical methods which must be checked by replication and validation of new knowledge via peer review.
Objectivity distinguishes scientific knowledge from any other sources of information.
Taking an objective approach to an issue means having regard for the known valid evidence about that issue.
other researchers should be able to repeat any study and get the same information.
Miller (1956) - the capacity of the short term memory is 7+/- 2 items. This has been tested by generations of psychology students ever since and the same results found. Millers findings are replicable.
The hypothetico-deductive method
1. The hypothesis
2. Test hypothesis
3a. Do not support the hypothesis (if the results of the tests are inconsistent with the hypothesis and do not support it)
3b. Support the hypothesis
4. The theory (the findings of research that support the hypothesis allow us to begin to form a theory or modify one that already exists)
Karl Popper (1902 - 1994) says a theory can only be scientific if it is falsifiable. this means that it has to be possible to either prove or disprove the theory.
Thomas Kuhn (1922 - 1996) says that science operates within a given paradigm (a theoretical framework) which defines the way in which research is conducted. Because scientists are dedicated to their paradigm, they only seek to find supportive evidence that fits their accepted assumptions of science, and they disregard contradictary evidence.
It is possible for one paradigm to overthrow another until it becomes accepted as the dominant paradigm (a paradigm shift).
He concludes that science is not objective as it is what the scientific community accepts as scientific.
Laws and principles
A scientific law or principle is a statement that describes the behaviour of things in the real world. They are a development of a theory - when a theory is tested and retested and their is enough evidence in its favour ir can be developed into laws and principles.
However it's not always possible to text every single aspect of a theory in every single scenario, so if it usually works and if every observed case provides the same result we can apply inductive reasoning meaning that we induce that the same thing will happen for all cases.
Is psychology a science?
There are many approaches (biological, cognitive, behavioural etc). Each has different underlying principles and methods, but they can all be applied to the same issue (e.g. explaining mental illness)
This suggests that psychology has not yet reached the stage of a true science as if does not have a single paradigm.
When psychologists develop theories they test them and publish their findings in peer-reviewed journals (other professionals in the area of psychology evaluate each others work)
This disseminates information - many people worldwide can benefit from new developments
It also provides a forum for critical appraisal (potential articles for publication are vetted by an editorial board, some journals invite comments from readers, other researchers can replicate the research to verify findings)
However, non-significant findings or replications of earlier studies are less likely to be published - 'file-drawer problem'. Academic journals are extraordinarily expensive and many university libraries can only afford a small number each year.