In an experiment the researcher assigns the treatment, ideally at random. In an observational study the researcher only records what people already do. Only an experiment can show cause and effect.
Observational study or experiment? A survey records how many hours teens spend on phones and how many hours they sleep.
Researchers follow 1,000 adults for ten years, recording how much they walk and whether they develop heart disease. Is this an observational study or an experiment? Name the explanatory and response variables.
Observational study or experiment? A hospital reviews records to compare the birth weights of babies born to mothers who did and did not smoke.
A census records household income and the number of books in each home. Is this an observational study or an experiment? Name the explanatory and response variables.
A coach randomly assigns swimmers to two warm-up routines and records their race times. Is this an observational study or an experiment? Name the explanatory and response variables.
Doctors review the records of 2,000 patients to compare coffee drinking with blood pressure. Is this an observational study or an experiment? Name the explanatory and response variables.
Observational study or experiment? A survey asks adults how often they exercise and how many sick days they took last year.
A doctor randomly assigns patients to physical therapy or rest and measures recovery time. Is this an observational study or an experiment? Name the explanatory and response variables.
Observational study or experiment? Researchers randomly assign 60 mice to a high-sugar or a normal diet and measure their weight gain.
Researchers randomly assign 100 volunteers to take either a new sleep aid or a placebo, then record hours of sleep. Is this an observational study or an experiment? Name the explanatory and response variables.
A school randomly assigns classrooms to start at 8:00 or 8:45 and compares attendance. Is this an observational study or an experiment? Name the explanatory and response variables.
A company randomly assigns 200 website visitors to see one of two page designs and records whether each one signs up. Is this an observational study or an experiment? Name the explanatory and response variables.
Observational study or experiment? Researchers randomly assign 80 drivers to use a hands-free phone or no phone in a driving simulator and count their errors.
A gardener randomly assigns 30 tomato plants to be watered daily or every other day and weighs the tomatoes each plant produces. Is this an observational study or an experiment? Name the explanatory and response variables.
Researchers survey 400 workers about how long they commute and how satisfied they are with their jobs. Is this an observational study or an experiment? Name the explanatory and response variables.
A city records the number of trees on each street and the average summer temperature there. Is this an observational study or an experiment? Name the explanatory and response variables.
Observational study or experiment? A farmer randomly assigns 40 plots to two fertilizers and measures the corn yield of each plot.
Observational study or experiment? A study compares the test scores of students who ride the bus with those who are driven to school.
A nutritionist randomly assigns 50 adults to eat breakfast or skip it for a month and measures their energy levels. Is this an observational study or an experiment? Name the explanatory and response variables.
Observational study or experiment? A study compares the grades of students who play sports with those who do not.
Observational study or experiment? A survey records how many hours teens spend on phones and how many hours they sleep.Observational study
Researchers follow 1,000 adults for ten years, recording how much they walk and whether they develop heart disease. Is this an observational study or an experiment? Name the explanatory and response variables.Observational study; explanatory: how much they walk; response: whether they develop heart disease
Observational study or experiment? A hospital reviews records to compare the birth weights of babies born to mothers who did and did not smoke.Observational study
A census records household income and the number of books in each home. Is this an observational study or an experiment? Name the explanatory and response variables.Observational study; explanatory: household income; response: number of books
A coach randomly assigns swimmers to two warm-up routines and records their race times. Is this an observational study or an experiment? Name the explanatory and response variables.Experiment; explanatory: the warm-up routine; response: race time
Doctors review the records of 2,000 patients to compare coffee drinking with blood pressure. Is this an observational study or an experiment? Name the explanatory and response variables.Observational study; explanatory: coffee drinking; response: blood pressure
Observational study or experiment? A survey asks adults how often they exercise and how many sick days they took last year.Observational study
A doctor randomly assigns patients to physical therapy or rest and measures recovery time. Is this an observational study or an experiment? Name the explanatory and response variables.Experiment; explanatory: the treatment; response: recovery time
Observational study or experiment? Researchers randomly assign 60 mice to a high-sugar or a normal diet and measure their weight gain.Experiment
Researchers randomly assign 100 volunteers to take either a new sleep aid or a placebo, then record hours of sleep. Is this an observational study or an experiment? Name the explanatory and response variables.Experiment; explanatory: which pill a volunteer takes; response: hours of sleep
A school randomly assigns classrooms to start at 8:00 or 8:45 and compares attendance. Is this an observational study or an experiment? Name the explanatory and response variables.Experiment; explanatory: the start time; response: attendance
A company randomly assigns 200 website visitors to see one of two page designs and records whether each one signs up. Is this an observational study or an experiment? Name the explanatory and response variables.Experiment; explanatory: the page design; response: whether the visitor signs up
Observational study or experiment? Researchers randomly assign 80 drivers to use a hands-free phone or no phone in a driving simulator and count their errors.Experiment
A gardener randomly assigns 30 tomato plants to be watered daily or every other day and weighs the tomatoes each plant produces. Is this an observational study or an experiment? Name the explanatory and response variables.Experiment; explanatory: how often the plant is watered; response: weight of tomatoes
Researchers survey 400 workers about how long they commute and how satisfied they are with their jobs. Is this an observational study or an experiment? Name the explanatory and response variables.Observational study; explanatory: commute length; response: job satisfaction
A city records the number of trees on each street and the average summer temperature there. Is this an observational study or an experiment? Name the explanatory and response variables.Observational study; explanatory: number of trees; response: average summer temperature
Observational study or experiment? A farmer randomly assigns 40 plots to two fertilizers and measures the corn yield of each plot.Experiment
Observational study or experiment? A study compares the test scores of students who ride the bus with those who are driven to school.Observational study
A nutritionist randomly assigns 50 adults to eat breakfast or skip it for a month and measures their energy levels. Is this an observational study or an experiment? Name the explanatory and response variables.Experiment; explanatory: eating breakfast; response: energy level
Observational study or experiment? A study compares the grades of students who play sports with those who do not.Observational study
A researcher records how many hours of TV 500 children watch and their reading scores.
Nobody is told how much TV to watch; the researcher only records it.
TV is what might explain the scores, and the reading score is what is measured.
The answer is Observational study; explanatory: hours of TV; response: reading score.
Where students go wrong
Concluding cause from an observational study. Children who watch more TV may differ in many other ways, and any of them could explain the scores.
Also called observational study vs experiment or explanatory and response variables.
Questions about these worksheets
Yes. Every observational studies and experiments sheet is free to print and free to download as a PDF. There is no account to make, no email to hand over and no limit on how many you take.
Yes. The answer key prints on a second page, and you can choose whether it shows each question beside its answer or just the answers in a list.
Yes. Print straight from the page, or download the PDF and print that. The sheet is laid out for paper rather than squeezed off a screen, so there is room to work under each question, and the answer key comes out on its own page.
Statistics is usually taken around 11th or 12th grade, though schools vary and plenty of students meet it earlier or later. Pick the difficulty rather than the grade: the easy level suits a first lesson on it, the hard level suits review before a test.
Yes, as many as you like. The questions are built fresh each time rather than picked from a fixed set of files, so pressing Generate gives a new sheet. That is what you want for a second class, a retake, or two students sitting next to each other.
That is the closest comparison, and Kuta Software is good software. It is also paid software you install on a computer. These worksheets run in a browser tab for free, with no account and nothing to install. Like Kuta, the observational studies and experiments questions are generated when you ask for them rather than pulled from a fixed set of files, so two classes never get the same sheet, and the answer key comes with it.
Yes. There are three levels, and you can tick more than one for a sheet that mixes them, in which case the questions come out easiest first. The harder levels are not just larger numbers: they ask for something the easy ones do not.
Concluding cause from an observational study. Children who watch more TV may differ in many other ways, and any of them could explain the scores.