Scattergraph Correlational Analysis
If psychologists decide to use a correlation scattergraph to measure their results then both their IV and DV can be measured numericaly such as the longer you spend in day care the more aggresive you are. This shows the relationship between the two varibles and can easily be compared. You can analyse the data by comparing the strength of the results. Such as if there is a strong, positive relationship the you can say the correlational co-efficient is 0.9 or if it is a stong negative relationship then the correlational co-efficient would be -0.9. If there is no relationship the it would be 0.
A negative of using a scattergraph is that there may be extrainious or a 3rd varible affecting results such as the attachment type of the child in how aggresive they are in daycare.
A Lab Study is an artificial environment where most of the variables can be controlled by the experimenter. Strengths of this method are because we can control all the variables we know what causes the DV so it has good internal validity. Also they are easy to replicate so it has good reliability. Weaknesses however are that participants may know they're being watched so they may act differently and show socially desirble behaviors reducing the internal validity of the experiment. Also the situation is artificial so it has low ecological validity as it can't be generalized to real life.