Types Of Experiments
- Conducted in laboratory
- Conducted in tiled environment-subjects everyday life
- Conducted in during naturally occurring events.
Because of the artificiality of situation the subject may not always act like as they would in real life.
Can be replicated, repeated and verified.
Methods of data collection for development studies
Because of the demand of measuring behavioral change across different ages, several unique methods are used. The most frequently used are cross-sectional and longitudinal studies.
Cross Sectional Study
In a cross sectional study people of different ages are assessed on one occasion. This study thus provide information about differences in development between age groups.
To study the development of intellectual ability in adulthood a sample from different ages 25, 45, 65 can be given to them to compare their scores at the end. the researcher can then determine whether average IQ scores differ in each group.
Its advantages include the speed with which the studies can be conducted and the economy.
Its advantages are that it looks at group averages thus, the individual differences are overlooked. people with different ages, being born in different generations have influence on their intellectual and developmental ability but the cross-sectional studies can not eliminate these generational influences.
In this type of study the same people are studied again through different ages to learn about the developmental changes occurring in them with age.
These studies assess changes in behavior overtime whereas cross-sectional studies assess differences among groups of people.
To test the intellectual ability of 20 years old son an IQ test can be given to them and then again at all the age of 40 and then again to the same people when aged 60 this will show how intelligence varied with age and how development has occurred, requires a lot of time and effort also it is expensive
"Practice effect" of the tests takers can make them do better in future tests as they would have become 'Test-Wise'.
To overcome the drawbacks of both, cross-sectional and longitudinal studies, sequential studies are evolved.
It examines a number of age groups and at several points in life. the results are analysed to determine the differences that show up with age for the different groups of subjects.
Provides more realistic assessment than either the cross-sectional method (which tends to over-estimate the IQ ) decline with age.