Identify two problems researchers experience in collecting data from a sample

Inappropriate Sampling size/technique

Decline in survey response/giving inadequate responses

Explanation:

Researchers sometimes anticipate getting the smallest sample size to generate outcomes to the study, moreover, the sample size should reflect a true representation of the population, else, the research will be bias.

Decline in survey response is a big challenge in collecting data, sometimes, participants just tick questionnaires and do not go through the questions with sincererity. They are often in haste to conclude and return the questionnaire.

answer; /// i believe the correct answer is (when one group has an extremely high score at pretest;