Descriptive investigations involve collecting data about a system, but not making tests or experiments.
Making tests belongs to experimental investigations.
Descriptive investigations aim to draw conclusions from observations of the fenomena, while experimental investigations design tests that let the researcher to compare results on different conditions with a control situation.
There is also the so called comparative investigations which collect data from under different conditions but do not include the control situtation.
Agriculture is the way you make money through farming and ranching
Demographers are scientists who study human populations. They tend to map and understand the dynamics of population, which includes birth, death, and migration. All of these affects population and must be studied by demographers. They may study the population change within a country or the interrelationship of countries' populations, which is mostly necessary in studying migration. However, they could also take specialization. For example, they could study only parts of the population like workers' social pattern. Demographers mainly use statistics in mapping their data.
Answer:
These researchers are suffering from observer bias.
Explanation:
Observer bias is also known as <em>research bias</em> and it is the tendency an individual has to <em>see what he/she wants or expects to see</em>. The researcher allows his/her expectations about what will happen to <em>affect the study's results</em> because one's subjectivity comes into play, not really being objective.