explain two reasons why psychologists use a systematic method for collecting and analyzing research data.

Brief Explanations:

1. Reliability: A systematic method ensures consistent data - collection and analysis, allowing for replication of studies. This consistency helps in establishing reliable results across different researchers and settings.
2. Validity: It helps in accurately measuring what is intended to be measured. By following a set procedure, psychologists can minimize bias and confounding variables, thus enhancing the validity of their findings.

Answer:

1. To ensure reliability through replication.
2. To enhance the validity of findings by minimizing bias.