evaluation

• research bias as bowbly diagnosied each child and knew which ppts were thieves which reduces the internal validity
• bowlby used a case study method and the collection of data was "unsystematic and unplanned" so it would be difficult to replicate and lowers the external reliability
• by using case studies, Bowlbys methodology has high ecological validity as there is no artificial manipulation. therefore, his study has high external validity as findings can be generalised
• it can be argued that the sample used was unrepresentative of the target population as the group was from one area and ppts were selected through oppourtunity sampling which limits how far the findings can be generalised
• ermisch and francesconi - supporting research showing that children who mothers returned to work before they start school have slower emotional development and scored less well in reading and math tests
• contradicting research evidence- Bowlbys earlier work with children seperated from their mothers due to prolonged time in hospital with tuberculosis and showed little long term consequences which suggests conclusions of the 44 thieves may not be entirely relaible
• a strength of the procedure was that Bowlby used a control group of 44 children who were matched on age, intelligance and economic status therefore he could directly compare results
• Bowlby used interviews which could lead to social desirability which reduces the internal validity
• an ethical issue is valid consent as the interviews were done in 1936-39 but the report wasnt published till 1944 so its likely ppts were unaware their data was being used
• ethical guidelines were not published at the time
• positive social implication- by highlighting negative effects of maternal deprevation hospitals now have round the clock visiting times
• positive social implication- nursuries now have a low staff to child ratio to ensure attachments can be formed
• a negative social implication- implies that any regular seperation from the mother can have damaging consequences and could lead to women not going back to work and skill gaps