decide if each of the following describe an observational study or an experiment. the haircolor of shoppers…

decide if each of the following describe an observational study or an experiment. the haircolor of shoppers at the mall was recorded. a drug is given to a group of people, and their reactions observed. a group of students are told to listen to music while taking a test and their results are compared to a group not listening to music. the temperature on randomly selected days throughout the year were measured. the gender of children born in january were tallied. the growth rate of bacteria is compared before and after adding alcohol.

decide if each of the following describe an observational study or an experiment. the haircolor of shoppers at the mall was recorded. a drug is given to a group of people, and their reactions observed. a group of students are told to listen to music while taking a test and their results are compared to a group not listening to music. the temperature on randomly selected days throughout the year were measured. the gender of children born in january were tallied. the growth rate of bacteria is compared before and after adding alcohol.

Answer

Brief Explanations:

  • The haircolor of shoppers at the mall was recorded: This is an observational study. The researcher is simply observing and recording a characteristic (hair - color) of the shoppers without interfering or manipulating any variables.
  • A drug is given to a group of people, and their reactions observed: This is an experiment. Here, a treatment (the drug) is deliberately administered to a group, and the response (reactions) is observed.
  • A group of students are told to listen to music while taking a test and their results are compared to a group not listening to music: This is an experiment. There is an intervention (telling one group to listen to music) and a comparison of outcomes (test results) between two groups.
  • The temperature on randomly selected days throughout the year were measured: This is an observational study. The researcher is just measuring the temperature (a natural variable) on selected days without any manipulation.
  • The gender of children born in January were tallied: This is an observational study. The researcher is observing and counting the gender of children (a natural occurrence) without any intervention.
  • The growth rate of bacteria is compared before and after adding alcohol: This is an experiment. An intervention (adding alcohol) is made, and the effect (change in growth rate) is observed.

Answer:

  1. Observational study
  2. Experiment
  3. Experiment
  4. Observational study
  5. Observational study
  6. Experiment