Beacon Lesson Plan Library

Qualitative vs. Quantitative

Summer Zephyr
Bay District Schools

Description

Students examine the difference between qualitative and quantitative observations by doing a simple lab activity. This lesson can be used at any grade level. It involves the basic observation process skill.

Objectives

The student understands that no matter how well one theory fits observations, a new theory might fit them as well or better, or might fit a wider range of observations, because in science, the testing, revising, and occasional discarding of the

Materials

- A book for teacher demonstration
- Tape measure or ruler for teacher demonstration
- A triple beam balance for demonstration and one for each group of students
- Green leaf
- Lotion
- Concrete Block
- Dried Leaves
- Plant
- Paper Clips
-Sourball
-Ruler (set for each group) .
-Activity Sheet for each student (See attachment)
-Cube of sugar or peppermint (for each student in the group).

Preparations

1. Gather: plant for desk, book, leaf, bottle of lotion, sourball, concrete block or brick, peppermints (in wrappers) for each student, dried leaves, thermometer, ruler, balance (for demonstration), Balance, ruler set (for each group)

2. Make a T-chart on board (quantitative-qualitative)

You may want to create a checklist to be used by you (the teacher) as students are working in their groups to evaluate Goal 3 (information managers and cooperative workers.) For example.
Information mangers:
Student takes legible notes.
Student puts title of work on paper, name, date, and period.
Student completes all work correctly.

Cooperative learner:
Student listens to other members of group.
Student does assigned task.
Student encourages other group members to get work done.
Student helps others when needed, but does not do the work of the other members.

Procedures

1.Go over background information with students in a whole group situation. (By observing we learn about the fantastic world around us. We observe objects and natural phenomena through our senses: sight, smell, touch, taste, and hearing. The information we gain leads to curiosity, questions, interpretations about our environment, and further investigation. Ability to observe is the most basic skill in science and is essential to the development of other science process skills such as inferring, communicating, predicting, measuring and classifying. ( See Beacon Lesson:Observing through the Senses in Weblinks)


2. Make a T-chart on the board and write quantitative on one side and qualitative on the other side. As the lesson progresses, question the students about the characteristics of quantitative and qualitative and write answers in the respective places.

3. Explain:
When we want more precise information than from our senses alone, we include a reference to some standard unit of measure, such as inches, centimeters, pounds, grams, Fahrenheit or Celsius. Observations that involve number or qunatity are quantitative observations. When we count, weigh or measure an object this is quantitative observation (analysis).

4. Show students a tape measure and measure a book.

5. Show a balance and weigh the book.

6. Show a thermometer and try to take the temperature of the inside of the book. Read thermometer of air temperature first to see if there is a change.

7. Explain:
These are examples of quantitative observations. Anything you measure is quantitative. Quantitiative observations help us communicate specifics to others and provide a basis for comparisions.Qualitative observations provide information in which you used only your senses.

For example:
(Ask students to identify qualitative observations and list them on the T-chart.)
It is green in color. (sight) (Show a green leaf.)
It has a sweet odor. (smell) (Show a bottle of lotion.)
It tastes sour. (taste) (Show a sourball.)
Its leaves are rough and hard. (touch) (Show a concrete block.)
It makes a rustling sound when rubbed. (hearing) (Show a handful of dried leaves.)
Each of the objects that we observed can also be quantified.

8.Select the leaf and have a student come up and weight it and measure it. Ask, -Can this leaf be measured for heat?- Yes, it can but not very accurately with a thermometer. A temperature probe might show a change in temperature a little better than an oral thermometer.

9.Take a plant that is sitting on the desk and say:
Quantitative observations could be made about this plant. Measure one leaf, length and width. (metric ruler)
The mass of one leaf is________. (Weighs with balance)
The temperature of room in which it grows is____ . (Thermometer)
The plants leaves are clustered or grow singly on stem.
This plant is larger than that plant. (This shows comprison if you have another plant in the room.)
Each leaf is as wide as three paper clips. (Shows quantitative observation without using metric tools.)

10. Explain:
Quantitative observations made with instruments such as rulers, meter sticks, balances, and graduated cylinders or beakers, give us specific and precise information. Although approximations and comparisons are not as precise, they are also quantitative observations.

11.Divide the students into groups of three or four.
Have one student go get a candy for each in group, the measurement set, and activity sheets for each student. Students supply their own pencils. Students share the measurement tools.

12.Students fill out the Activity Sheet.

13. At the end of the Actitvity Sheet, students go back to whole group and discuss their results of the activity with teacher and other students. Students hand in their papers to teacher.

Assessments

This assessment is a formative assessment only. Assess students during whole group discussion which occurs at the end of the lesson. Check student answers on their activity sheets and assign a grade if desired when using the Student Self-check sheet and Answer Key.

Students can also compare their answers with their neighbors.

I prefer to have students go back to whole group and I go over the answers using the overhead. Students Self-Check and discuss with teacher.

Teacher may ask students:
How many of your answers were the same as those found on the Self-check list?
Explain which type of observation, qualitative or quantitative, is the most objective.
Students explain the importance of observing the same things often and comparing them.
You may want to have students defend the need to make observations and comparisons.

Answer Key (Make your own measurement ahead of time)

Qualitative Observations:
1.Object is round shaped, white, red
2.Tastes sweet
3. Smells like peppermint
4. Feels hard, texture smooth
5. Makes a sharp sound when dropped (on desk)

Qualitative Observations: (Senses)
1. Sight
2.Taste
3. Smell
4. Touch
5. Hearing


Quantitative Observations:
1. Length: 1.5 cm (make your measurements ahead)
2. Width: 1.5 cm
3. Height .5 cm
4. Mass (weight)

Quantitative instrument used:
1. metric ruler
2. metric ruler
3. metric ruler
4. balance

Web Links

Web supplement for Qualitative versus Quantitative
Observing Through the Senses

Attached Files

A student worksheet to be used during the activity.     File Extension: pdf

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