Elementary Science

Science Focus LessonWeek 3

Polk County Public SchoolsLinda Vendur, Senior Coordinator

Week 3 – SC.H.1.2.1Benchmark: The student knows that it is

important to keep accurate records and descriptions to provide information and clues on causes of discrepancies in repeated experiments.

Essential Question:Why is it important to keep accurate records

when doing an experiment?

Vocabulary:data repeated trials

measurements metric units

Gathering the Data We do investigations to get information.The pieces of information collected during an

investigation are called data.Data are sometimes in the form of simple

observations.Other times data are collected in the form of

measurements.

Why do you think scientists keep careful

records of the data they collect during their investigations?

Why do you think scientists keep careful records of the data they collect during their investigations?

So they won’t forget or get confused about what happened during the investigation.

So later they can look for repeating patterns in the data.

So they can repeat their own investigation to get more data.

So other scientists can replicate the investigation.

Did you think of any other reasons?

When collecting data remember….Record all data right away directly into

your log. This will ensure that errors are not made copying data from one place to another.

Record carefully so the information is accurate.

Show the units of measure, not just the numbers.

Use metric units when you take measurements.

Never cross out or change the data.

Why should we not cross out or change the data?

Measuring in MetricsScientists use metrics when making their measurements.

They do not use standard measurements and then convert to metrics.

What is Measured

Metric Unit

length meter (m)

mass gram (g)

weight newton (n)

volume liter (L)

Temperature Degrees Celsius

What kind of tools would you use for each measurement?

SummarizingAnswer the question in your Science notebook.

What are some things scientists do so they are able to share information?

Repeated TrialsEach time you conduct a test or

observation is called a trial.The more times you do a test or

observation and get the same results, the more you can trust the data you collected.

One way to improve an experiment is by doing more trials. The more trials, the more reliable the results.

What Now???? What does it mean if you do 5 trials of your experiment

and you get different results on

some of the trials?

What should you do?

Talk about it with your group.

Hannah’s mother wants to plant a garden in the spring and needs to know how deep to plant pea seeds. To help her mother, Hannah designed an experiment. She layered small stones and soil in an aquarium. She then planted four pea seeds at four different depths in the soil. She placed the seeds at depths of 1.0 centimeters (cm), 2.0 cm, 4.0 cm, and 6.0 cm below the surface of the soil. Hannah watered the seeds and put the aquarium in a sunny location.

How Does Your Garden Grow?

A Record when the seeds sprout and begin to grow.

B Make sure the seeds have enough sunlight.

C Predict which seeds will sprout.

D Plant more seeds.

What should Hannah do next in order to have useful information for her mother?

An understanding of the reasons for keeping records during an experiment is needed to answer this question. Hannah’s mother wants to know which depth is best to plant seeds. Hannah should first record how long it takes the seeds to sprout. Hannah can analyze the data and draw a conclusion about which seeds sprouted to answer her mother’s question.

The correct answer is A…

Record when the seeds sprout and begin to grow.

B. Providing enough light will be important for plants, but this will not have a major impact on the sprouting of seeds planted under the surface.

C.Hannah could make a prediction, but this would not give her mother any specific information from the experiment.

D.Hannah has planted four seeds at each depth, so planting more seeds would not provide any information.

SummarizingHannah wanted to know how deep toplant her seeds so they would grow best.How can we find out the answers to some of the questions we have about nature? What are some of your questions?

Answer in your Science notebook.

Mrs. Patterson’s class is growing red oak seedlings to transplant into a nearby park. Mrs. Patterson divided the class into groups and asked them to decide the best way to record how fast the seedlings grow. The data tables from the different group are on the next slide.

Look at the next slide and decide which data table would be the most helpful in verifying how fast the seedlings grow?

F H

G I

Data should be collected and recorded so that it is clear how much time passed between each measurement of plant height. The data chart for the seedlings should be clear about when data were collected so that the growth of the seedlings can be compared over a specific time interval.

The correct answer is H, data table #3.

SummarizingAnswer the Essential Question for the lesson in your Science

notebook.

Essential Question:Why is it important to keep accuraterecords when doing an experiment?

Checking For Understanding1. What is the best way to check the

accuracy of your data collected during an experiment?A. Change the experimentB. Estimate the measurementsC. Make a data tableD. Repeat the experiment

2. Amy watered bean plants with three different liquids for her science fair project. To be sure her results were correct, she repeated her experiment two more times. The last time she did her experiment, none of the plants grew.

What should Amy do?A. Make up data for the last experiment.

B. Study her observations to find out why the last experiment was different.C. Average her data from the first two experiment to use as data for the third experiment.D. Look online to find data to fill in for the last experiment.

3. Zack and Josh did the same lab activity from their science book. When they compared their data they found out that they got very different results.

What should they do next?A. Throw out their data and copy someone else’s data.B. Ask the teacher who is correct.C. Review their experiments to see if they can tell what caused the difference.D. Use Josh’s data because he is a better student

4. A famous scientist did an experiment and published his results. When a scientist in another country repeated the experiment he got very different results.

What should the second scientist do?A. Tell everyone the first scientist is wrong.B. Decide his results must be wrong.C. Review both experiments to determine why the results were different.D. Change his data to match the famous scientist’s data.

5. Tara is doing the same experiment as her friend Jessica. At the end of the week, Tara calls Jessica. She finds out that Jessica’s experimental data is very different from hers.

Which of the following is the MOST likely cause of the difference?A. Tara is measuring accurately and Jessica is estimating.B. Jessica has done the experiment beforeC. Tara and Jessica have different science teachers.D. Tara knows more science than Jessica does.

Check Your Answers1. D. Repeat the experiment.2. B. Study her observations to find

out why the last experiment was different.

3. C. Review their experiments to see if they can tell what caused the difference.

4. C. Review both experiments to determine why the results were different.

5. A. Tara is measuring accurately and Jessica is estimating.

SummarizingScientists working to develop new medicines

often test new drugs by using repeated trials. Why is it important that they conduct

repeated trials before putting new medicines on the market?

What could happen if they did not repeat their trials many times?