Planting Seeds, Part 1: Can You Design a Fair Test?info.ritenour.k12.mo.us/RSD/science_exemplars/k_5/pdfs/task731.pdf · Pots are placed on plastic trays in ... to determine how many

Planting Seeds, Part 1: Can YouDesign a Fair Test?

In this investigation, your team will choose 2 or 3 seeds in orderto design an investigation to learn something more about them.First, you will need to think about something you would like tofind out and how you might test it. Make a list of what you willuse and what you will need to measure. Make a predictionabout what you think will happen, and tell how you will be surethat it is a fair test. You will use your observation data to tellyour results and make some conclusions about what you havelearned.

1 of 12Planting Seeds, Part 1: Can You Design a Fair Test?

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Planting Seeds, Part 1: Can You Design a Fair Test?

Suggested Grade Span

3–5

Task

In this investigation, your team will choose 2 or 3 seeds in order to design an investigation tolearn something more about them. First, you will need to think about something you would liketo find out and how you might test it. Make a list of what you will use and what you will need tomeasure. Make a prediction about what you think will happen, and tell how you will be sure thatit is a fair test. You will use your observation data to tell your results and make someconclusions about what you have learned.

Big Ideas and Unifying Concepts

Cause and effectChange and constancyForm and functionInterdependenceSystems

Life Science Concepts

Evolution, diversity and adaptationsPopulations and ecosystemsRegulation and behaviorReproduction and heredityStructure and function

Mathematics Concept

Data collection, organization and analysis

Time Required for the Task

Approximately two to three classes for Part 1 (planning and planting) and five to ten days forPart 2 (collecting data and reporting results).



Context

This investigation was done last spring as part of a unit of study about plants. To introduce theconcepts of fair tests and testable questions, students were given the opportunity to explorehow selected seeds grew under certain conditions. First, as a class we brainstormed manyquestions that we could test, such as: Which seed will grow the tallest? Which seed will sproutthe fastest?

Then, I modeled collecting data using a recording sheet, “Investigation Planner,” from ScienceAlive: A World of Matter classroom materials, and we completed one sample together. Whenstudent teams began to plan their investigations, they had some understanding of the topic aswell as a basic idea of the skills of scientific investigation.

What the Task Accomplishes

This task provides information to the teacher about whether students have a clearunderstanding of how to apply the scientific method (controlling variables and collecting,recording and interpreting data) when designing their own investigation. In Part 1, the focus ison planning the investigation as a fair test. Assessment at this point in the investigation assiststhe teacher in being able to ensure that students will modify their designs, if needed, beforecollecting their data.

How the Student Will Investigate

The first half of the recording sheet, “Investigation Planner,” is used to guide students throughthis part of the investigation. Once teams select a testable question, they make a prediction andplan what materials they will use. Before conducting their tests, their plan is reviewed andmodifications or clarifications can be made. Students then plant seeds and record observationsin drawings and words to share with the class.

Because students work in teams, fewer materials and less space are necessary for individualprojects. Cooperative groups have assigned roles (materials manager, information recorder,overseer/timekeeper) to complete the planning and planting. Pots are placed on plastic trays inthe GrowLab for observation.

Each student makes individual observations in a journal, but the team collaborates to producethe final report. New roles can be assigned for Part 2 by having an artist and recorder completeeach day’s observations for the team and having others check for accuracy and completeness.

Interdisciplinary Links and Extensions

ScienceStudents can test the germination rates found on the seed packets or compare year-old seedsto current-year’s seeds. If planted in groups of 10 seeds, percentages are also easy to compute(i.e., 6 of 10 seeds germinated in three days = 60%). Students can test how different soils affect



the rates of growth of plants and the germination success of seeds. Students can test theeffects of different planting depths on the same seeds and determine optimum depths. (Ifplanted too deep, most seeds will not be able to make it to the surface of the soil; too close tothe surface, roots may not take hold well, seeds are likely to be eaten by birds, etc.)

Art/WritingStudents can design seed packets for new hybrids or to describe themselves! These makecolorful classroom posters.

MathematicsStudents can plan “backwards” for a garden, planting seeds at different times to have a harvestat the same time. (For example, they could map out dates to plant each type of seed for abouquet of cut flowers or ingredients of a tossed salad.) Students can dissect a plant (such as amarigold or seedpod) to determine how many seeds one flower and one plant might produce.

Teaching Tips and Guiding Questions

Life science topics that involve planting seeds, transplanting and propagating plants, andobserving plant growth under different conditions are great activities for the spring months.Students are learning concepts related to plants as well as becoming more familiar withapplying the scientific investigation process and designing fair tests.

Guiding questions to ask students at the beginning of this investigation might include:

• What is your testable question? What are your ideas about your question?• What have you learned or observed so far that will help you make a prediction or

hypothesis?• How will you test your question?• What are some possible variables to test? (length of germination, rate of growth, effects of

different planting depths for the same seeds, etc.)• What would happen if you ... ?• How will you control variables? (same number of seeds; same amounts of water, light, soil;

same container size; etc.)• What variable will you test? How will you make this a fair test?• What materials will you need?• What will you measure? What tools do you need?• How will you record your data?• How often will you make your observations?• Did you mark each seed type in its pot?• Have you learned anything that surprised you so far?



Concepts to be Assessed

(Unifying concepts/big ideas and science concepts to be assessed using the ScienceExemplars Rubric under the criterion: Science Concepts and Related Content)

Life Science – Structure and Function; Reproduction and Heredity: Students identifycharacteristics of organisms – each plant has different structures that serve different functionsin growth, survival and reproduction. Students understand the characteristics of seeds bydescribing some of their needs, aspects of their immediate environments, some of theirstructures (seed coat, root hairs, etc.), and the effects of weather or other events.

Life Science – Regulation and Behavior: Students understand that all organisms must be ableto obtain and use resources, grow, reproduce and maintain stable internal conditions whileliving in a changing environment.

Life Science – Evolution, Diversity and Adaptations: Students understand that speciesacquire many of their unique characteristics including, structures, behaviors or physiology,through biological adaptation that enhances survival and reproductive success.

Life Science – Populations and Ecosystems: Students identify some patterns of similaritiesand differences among plants and recognize their interdependence with other living things(systems and interdependence).

Scientific Method: Students observe and explain reactions with some justification, using dataand prior knowledge, when variables are controlled (cause and effect). Students determine thepatterns and/or which kinds of change are happening by making observations andmeasurements over time (change and constancy).

Mathematics: Students collect, organize and analyze data.

Skills to be Developed

(Science process skills to be assessed using the Science Exemplars Rubric under the criteria:Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data)

Scientific Method: Raising testable questions, predicting/hypothesizing, observing,collecting/recording data, interpreting data and drawing conclusions.

Other Science Standards and Concepts Addressed

Scientific Method: Students hypothesize, observe, predict, investigate and explainphenomena. Students control variables.



Scientific Theory: Students use evidence to construct an explanation based upon theirobservation and the concepts that have been learned. Students modify explanations when newobservations are made.

Life Science – Structure and Function: Students understand the characteristics of organisms(needs, environments, structures and behaviors), see patterns of similarity and differencesamong living organisms, and recognize the interdependence of all systems that support life.

Life Science – Evolution, Diversity and Adaptations: Students understand that organismscan survive only in environments that meet their needs, and that organisms have distinctstructures that have developed to help them to function and survive.

Life Science – Structure and Function; Reproduction and Heredity: Students observe thateach plant has different structures that serve different functions in growth, survival andreproduction.

Suggested Materials

Essential items to have available during these investigations include potting soil, cups or pots(or even washed out milk cartons), water and a variety of seeds with short germination times(under two weeks!). Many of our seeds had been donated by parents and the Parent-TeacherGroup. It is important for students to label their pots with what was planted so that they do notget mixed up during the observation weeks. Grow lights or a GrowLab were not essential, sincethis was primarily a seed germination activity. However, for extended investigations with plants,I would suggest having plants under lights. I also have measuring tools, such as rulers,eyedroppers and measuring cups, for students to use.

Possible Solutions

For each investigation, students generated their questions; therefore there are a variety ofpossible designs. What is most important in this investigation is that students demonstrate anunderstanding of how to control variables, record their data and accurately interpret the data.Each part of the planning form should be completed: (1) what we want to find out, (2) our ideafor an experiment, (3) materials needed, (4) what we will measure, (5) our predictions, and (6)how we will make it a fair test.

For the last two questions on the planning form (What actually happened? and What I foundout), I assessed to see if students collected data and stated results related to their originalquestion.

Task-Specific Assessment Notes

NoviceThese students state a question to answer, but the investigation does not seek to test a variableor compare different results. Materials are listed and there is some evidence of controlling



variables; however, only the amount of soil is the variable we are sure about. The interpretationof data shows little conceptual understanding about plants, since the students state that theflower became a weed.

ApprenticeThese students did complete the task, asking a testable question regarding the effects ofdifferent locations on plant growth; however, the actual investigation does not appear to followthrough with the original plan. There is evidence of understanding what variables to control.

PractitionerThese students include a testable question and show evidence of understanding fair testing andcontrolling variables. (Both plants are in the GrowLab and get 1/2 cup of water each day.) Theprocedures followed and the results based on data collected match what was planned to betested and measured. It is not clear how the plant is measured for growth, unless it is simply bymaking an observation.

ExpertThese students include a testable question and provide clear and detailed descriptions of theprocedures they followed. They note several ways variables are controlled using precisemeasurements (four squirts of water each day, each seed planted one inch deep). Thinking isextended when the students make comparisons with other plants in the room and dig up theirseeds to further observe what is happening. They consider modifying the investigation(changing amounts of water being used) based on their observations.



Novice



Apprentice



Practitioner



Expert



Expert



Documents

Planting Seeds, Part 1: Can You Design a Fair Test?info.ritenour.k12.mo.us/RSD/science_exemplars/k_5/pdfs/task731.pdf · Pots are placed on plastic trays in ... to determine how many