Primary Data: Primary data are gathered first hand from source directly by the researcher(s). For example, Milgram (1963) collected primary data during his study into obedience in a laboratory environment, and Bandura et al. (1961) collected primary data when they looked at children copying role models. Psychological studies usually gather primary data.
Secondary Data: Secondary data have already been gathered by someone and are then used by someone else in order to conduct further research. For example, a meta-analysis is where researchers pool together all of their pre-existing data on a specific topic. Craft et al. (2003) -sport psychology- and Bachrach et al. (1991) –psychodynamic approach- are both examples of meta-analyses.
Evaluating the use of primary and secondary data in research
| Primary Data | Secondary Data | |
| Strengths | ·Operationalisation is done with the research aim in mind, so there is likely to be validity with regard to the aim.
·More credible that secondary data, because they are gathered for the purpose with the chosen research method, design, etc. |
·Relatively cheap compared with primary data, as they are already collected.
·Can be in good quantity, so there might be detail ·Can be from different sources, so there is a possibility of comparing data to check for reliability and validity. |
| Weaknesses | ·Expensive compared with secondary data because the data has to be gathered from scratch.
·Limited to the time, place and number of Ps, etc., whereas secondary data can come from different sources to give more range and detail. |
·Likely to be gathered to suit some other aim, so may not be valid for the purpose of the study.
·When analysed to be presented as results, there may have been subjectivity. ·May have been gathered some time before, so not in the relevant time period. |
Use of primary and secondary data in clinical psychology
Hach et al. (2004) – looked at the frequency of mental disorders and the prescription of drugs for mental disorders in young women in Germany.
The sample was made up of 1555 18-25-year-olds. The aim was to consider the patterns of drug use in young women in Germany in relation to how common mental disorders were.
Researchers used a standardized interview to diagnose mental disorders using Axis 1 of the DSM-IV. The interview also asked them what medicine they were being prescribed. The researchers also gathered information about each women’s diagnosis from her doctor, using medical records, including the medicines prescribed. The interviews provided primary data and the doctor’s diagnoses and prescriptions were secondary data taken from the medical records.
For each woman, the DSM diagnosis from the interview and the doctor’s diagnosis were compared, as well as the medication the woman said she was on compared to the medication that was being used according to the medical records. From these comparison’s it was found that there was not much agreement between the diagnosis from the interviews and the doctor’s diagnosis. However, there was agreement on the medications prescribed.
The conclusion of the study was that the prescription of drugs by doctors for mental health issues should be checked, as the validity of the mental health diagnoses might be questioned.
This study shows that using both primary and secondary data can help to show the usefulness of one or the other. In this case, it might have led to questioning the doctor’s diagnosis.
Validity and reliability in clinical psychology
Validity is found in studies where what is measured is what is claimed to be measured. For example, if someone is studying anxiety and draws conclusions about it, then finds that the people being studied are suffering from depression, then the conclusions would not be valid.
Reliability is found when what was done in one study is repeated and the same results are found, For example, if someone links depression with loss in early childhood and then the study is repeated with different Ps (or even the same Ps) and there is no such link found, then the results lack reliability.
Such issues are important in clinical psychology, particularly with regard to diagnosing mental disorders. If one doctor diagnosis someone with depression and another gives the diagnosis of anxiety then that person would not think that they had been reliably diagnosed. The reliability of diagnosis is important for the individual, as treatment depends upon the diagnosis. If someone is not being treated for the right disorder then they are unlikely to improve. If the two doctors above are both using the same symptoms and the same manual to diagnose the same person with different mental disorders then the diagnosis is neither reliable nor valid. For a diagnosis to be valid it has to be measuring what it claims to measure. If a patient’s set of symptoms can be interpreted to be different disorders then the list of symptoms in the manual being used is not a valid measure.