The psychodynamic approach (PA) favours using methods such as case studies. Case studies give an insight into the workings of the mind as a phsychologist can build up an in depth detailed investigation into one person, or group of people. For example, Freud and Breuer worked together to study Anna O during her bouts of hysteria.
A strength of case studies is that they are high on validity. This is because they are based on studies of real life clients and produce qualitative data, rather than studying participants in artificial lab situations, giving rich detail. For example, Freud corresponded with Rat Man about his anxieties, gaining detailed information about the death of his father and other aspects of his life. This suggests that using case studies paints a true picture of behaviour, thus strengthening PA methodology.
A weakness is that PA case studies can be see as unethical. This is because some case studies lead to misinterpretation and hence incorrect treatment, placing the patient in a position of potential harm. For example, it is believed Freud misdiagnosed Anna O, and she in fact suffered from temporal lobe epilepsy were many of her symptoms (e.g imagined smells) are common side effects. This suggests that such methods may break ethical guidlines.
In addition, clinical interviews are also used as part of PA methodology. Over a period of time trust is established with the psychoanalyst, which means the patient opens up, revealing fears in their unconscious mind. For example, 'Wolfman' came to Freud with depression and discussed recurring nightmares about a pack of wolves.
A strength of clinical interviews is that they allow for individual differences (idiographic). Each client gives personal information, which allows interpretation of underlying meanings that may be more appropriate in capturing human experience than scientific methods. For example, Freud argued that Wolfman's recurring nightmares were due to his fear of castration by his father, in the phallic stage. This suggests that clinical interviews will lead to personalised outcomes and treatments.
However, one weakness of clinical interviews is they are low on reliability as no/little quantitative data is produced and there is little consistency between patients. Clinical interviews are also open to interviewer bias, making findings subjective. For example, Freud's analysis os Little Hans is open to alternative interpretations that may better describe his fear of horses, such as conditioning. In addition this method is not falsifiable (an essential factor in science). This suggests that PA methods cannot be repeated, retestes or generalised.