A clinical psychologist investigated the success of two different psychological interventions for adolescent anorexia nervosa: Dialectical Behaviour Therapy (DBT) and Family-Based Treatment (FBT). After a 6-month treatment period, patients' outcomes were classified as either 'Full Remission' or 'Partial Remission'. The psychologist wanted to determine if there was a significant association between the type of therapy received and the clinical outcome. The results are shown in Table 1.
Calculate the chi-squared (χ2\chi^2χ2) value for this data by completing Table 2. Show your calculations and state your final χ2 \chi^2\,χ2 value to 2 decimal places.
| Therapy Type | Full Remission | Partial Remission |
|---|---|---|
| DBT | 30 | 10 |
| FBT | 15 | 25 |
| Therapy | Outcome | Observed (OOO) | Expected (EEE) | O−EO-EO−E | (O−E)2(O-E)^2(O−E)2 | (O−E)2/E(O-E)^2/E(O−E)2/E |
|---|---|---|---|---|---|---|
| DBT | Full Remission | 30 | 22.5 | |||
| Partial Remission | 10 | 17.5 | ||||
| FBT | Full Remission | 15 | 22.5 | |||
| Partial Remission | 25 | 17.5 | ||||
| χ2\chi^2χ2 = |
Practise Edexcel A Level Psychology Research methods and skills with exam-style questions for A Level Psychology. 657 questions covering Research methods and skills, matched to the Edexcel A Level Psychology (9PS0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
