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Drop Device Inquiry: Investigating Liquids

This is a write-up of the design of a 3 hour staff development workshop on inquiry using liquids as a vehicle. This workshop was done with all the elementary teachers from Durham, North Carolina during the summer of 1994. Below is a brief description of the workshop, a template for the design of this workshop that can be used for other inquiry topics, and a list of questions that teachers asked after observing a drop device.

This workshop began with teachers observing a drop device (a cheap plastic novelty that has two or more colored liquids in it. When the device is turned over, one of the liquids forms round drops that sink through the other liquid, sometimes flowing down ramps, turning wheels etc). After observing for a short time, the teachers shared all the questions they had raised based on their observations. Then, the teachers were given a variety of household fluids like water, salad oil, rubbing alcohol (see list of materials below), and asked to use the materials to try to answer their questions. After their investigations, they discussed the experience and what they might do next if they had more time.

Introduction
The following outline is one way of considering and planning an inquiry-based science experience in the classroom. It describes the process of organizing the initial exploration with materials; discussing, summarizing, and clarifying questions for continued investigation; and developing further explorations and applications.

Considering the possibilities for children's learning in an activity can facilitate the progression from observation to investigation. Thinking through objectives can help you construct situations that stimulate students to ask questions and to undertake activities which help provide answers. Development of a concept is not achieved through a single activity but as a result of prolonged exploration and a wide variety of problem solving opportunities.

Below are 8 questions to ask to help design a particular inquiry topic. They are answered below for the topic of fluids.

1.  What are my objectives?
      A. What are the "big ideas"?
            1. Properties of matter
                Matter exists in solid, liquid, and gaseous forms.
                Liquids have certain characteristic properties: density, viscosity, surface tension, miscibility
         2. Introducing an inquiry method for doing science
      B.  What content area do I want students to investigate?
                Properties of matter through a study of liquids

II. What do students already know about liquids?
      A. Pre-assessment strategies
           What do students know about liquids?
           What questions do they have about liquids?
           Record what they say in some systematic fashion
           Use familiar material to focus attention: salad dressing
      B. Informal assessment
           Use students initial investigation with materials to assess prior knowledge

III. How will I introduce this topic?
      A. Observation of a drop device
           1. How can I help students make observations? 
               What do you notice happening?
               Tell me what you see...
               Did you notice that...?
               What questions do you have about?
           2. What questions might students raise? 
                Questions about: 
                     The liquids in the cylinder 
                     Drop rate/ speed of drops      
                     Construction of the cylinder 
                     Drop behavior 
                     The way things look through the cylinder
                     Role of air in the cylinder 
      B. Processing 
          How can I help students share their observations and questions?  
                    What did you notice?
                    What did you find out?
                    Do other people have the same questions?
                    What questions about liquids do you have now?
                    How might we go about answering some of these questions?

IV. What materials will best lend themselves to an investigation of this
       topic?
       A.  Are there everyday materials with which to begin an exploration?  
             Salad oil, mineral oil, water, salt water, clear detergent or shampoo, white vinegar,
             rubbing alcohol, Karo syrup, glycerin, food coloring
       B.  What additional materials will we need to facilitate our exploration?  
             Eye droppers, dropper bottles, test tubes or other clear containers, stoppers or corks, 
             stopwatches, waxed paper, newspaper, toothpicks, basins or buckets, paper towels,
             paper, markers, pencils, test tube holders
       C.  How do I make allowances for students' need to "mess about" with liquids  as an
            essential part  of  the initial exploration?
            Know that all students come to the exploration with different 
            experiences with liquids
            Know that familiarity with the substances is an essential 
            component of asking questions about their behavior
            Provide ample opportunity for students to explore the liquids 
            without a formal question to investigate

V.  What concepts might arise through an investigation with these materials? 
           Some liquids are heavier than others (density).
           Some liquids do not mix together (miscibility).
           Some liquids are thicker than others (viscosity).
           Some liquids stick together more than others (surface tension).

VI. How might we investigate these concepts in a systematic way?
       A. Identifying and formulating investigatable questions
            1. What questions do you have about liquids?
               Which liquids are heavier than other liquids?
               Which liquids mix together and which do not?
               Which liquids stick together to form bubbles?
               Does one kind of liquid form bubbles in all the other liquids?
            2. Which of these questions can we begin to find answers to?
            3. Can we restate other questions in ways that make it easier to look for
               answers?
       B. Planning systematic investigations
               Which question will you try to answer?
               What procedure will you use?
               What equipment and materials will you need?
               How will you record your observations?

VII. How will the results of these investigations be processed?
        A. Sharing in teams
               Formulate a summary of results
               Identifying other questions which were raised
        B. Sharing in the whole group              
               Communicate and discuss results based on observations
               Compare and interpret data
               Generate further questions
               Plan further investigations

VIII. How can we begin to apply the concepts in other ways?
         A. What are some applications of density? 
               How can you make something that sinks float?
               Why is it easier to float in ocean water than in fresh water?
         B. What are some applications of miscibility? 
              Why do some salad dressings stay mixed and others do not?
              Why do bottles of food, medicine direct to "shake well before using"?
         C. What are some applications of surface tension? 
              How can water striders and other insects walk upon the water?
              Which shapes of boats float upon the water?
         D.  Do all liquids distort the image of an object in the same way?
         E.  How do balls or bubbles behave on ramps of different shapes?
         F.  Is It possible to create a device with liquids or other fluids that keeps time?