Professional Development Tools for Inquiry-Based Science

©1998 The Exploratorium

Materials developed through a collaboration of the Exploratorium Institute for Inquiry and Wynne Harlen

The Process Circus: Developing the Process Skills of Inquiry-Based Science

When we interact with the physical and biological worlds around us in a scientific way, we find ourselves observing, questioning, planning, hypothesizing and interpreting. These actions are some of the process skills of science. Process Circus activities allow participants:

By actively engaging in a specially designed series of activities (12 activity stations) teachers begin to develop their own understanding of the process skills of inquiry-based science, and so are better able to develop these understandings with their students in the classroom. This activity also lays a foundation for later investigations that require understanding scientific processes, both for teachers in the classroom and for professional development specialists.

Aims of the Activity  

There are many different ways of naming and describing process skills and no one way is the 'right' one. A sometimes bewildering variety of interpretations of process/inquiry skills, their number, order, and relative importance, exists when one compares local or state frameworks and curriculum guides with national standards.  

While there is general agreement regarding what process skills are and their general order, their interpretation can vary from document to document. Precisely because there is a wide variety of interpretation of process skills, in this exercise we lay the groundwork for recognizing and establishing a common meaning, knowing full well that alternative interpretations and schemes for organization exist.  

How teachers think about science processes influences how they teach their students. The Institute for Inquiry's goal is for teachers and professional development specialists to view the use of science processes as a way to make sense of our physical surroundings by exploring, evaluating evidence and investigating the world around us. The 'working definitions' of process skills that participants develop, through doing and discussing the activities, are meant to describe scientific processes in terms of "what one is doing when using process skills." (Harlen, W. (1992). UNESCO Source Book for Science in the Primary School, p. 46.)  

The Process Circus itself is merely a method to foster group dialogue to identify and define process skills. The purpose of the activity is not to arrive at a 'correct' categorization, but to try to uncover and tease apart ambiguities and differences of understanding. For example, learners may believe that there is general agreement about the meaning of the process skill 'predicting', but reflection and discussion reveal that there are a variety of interpretations. Further more, while process skills such as observation may be routinely used, others, such as hypothesizing, may be less well understood.  

After developing mutually agreed upon definitions, teachers will be better able to develop skills such as questioning, hypothesizing , planning, and observing with their students in the classroom. Also, by recognizing the processes through which evidence is fairly used, teachers can help build their students' content understanding through their development (process skills). Then students can use these skills to move towards further and deeper science understanding.  

The Process Circus is not meant to be used directly as a science activity for students in the classroom, even though it is a valuable for professional development. However some of the activity stations within the Process Circus can be used as a way to highlight selected process skills for students in the classroom (such as observing, predicting or questioning).  

Process Skills Defined and Relationship to Standards  

For the purpose of simplicity, in this activity we use only five basic categories of process skills, knowing full well that a variety of other equally valid categories would suffice. Participants are asked to use the five categories below, to critique them, make changes, and additions or subtractions. Part of the work for participants is to create their own list of process skills and to define their meaning. Thus each group actively experiments with the Process Circus, activities and is free to modify or augment the list below in different ways.   The five suggested process skills are:

Each of these main categories subsumes processes that might be given separate status in other categorizations, in other texts, and in other standards documents. For instance, the category 'planning' in this scheme incorporates: 1. prediction; using past patterns of experimentation; 2. deciding which variable will be changed; 3. which results will be measured or collected as well as; 4. deciding what a 'fair' test might look like. And, although there is no one explicit process skill category listed for questioning, it can be folded into or made part of several of the larger categories. Some skills, such as observation and communication, will be used in almost every activity.  

Thus an important part of the work of participants is to determine if other skills (such as questioning, predicting, inferring) should be added to the five categories listed and to justify why the additions are important. The list is used as a starting point for discussion and should be revisited at the end of the activity after additions and changes have been made.  

We include Indicators of Process/Inquiry Skills in Action (Figure 1) in order to more fully describe activitiesthat underscore each of these five categories. In order to facilitate a free and open discussion the indicators, this list should not be handed out at the beginning of the activity.  

Figure 2, What Are Process Skills?---A Comparison of Interpretationsmakes specific comparisons of process skills described in the NRC National Science Education Standards, California State Science Framework, The FOSS Program, and AAAS Project 2061 Benchmarks. While there is disagreement in the number and general organization of categories, there seems to be a general agreement about the nature of the processes. Comparison reveals more similarities than differences.     

The Process Skill Activities in Outline  

Step 1: Setting the Context 

A brief overview of the purpose, goals, and value of the Process Circus
10 minutes)  

Step 2: Doing the Activities  

Partner-pairs do enough of each station/activity in order to identify the main process skill. They fill in Figure 1 as they do so. See Figure 4 for a separate list of stations.
(50 minutes) 

Step 3: Investigator Pairs Discuss Their Choices  

Partner-pairs review Figure 1 in order to identify the main processes used in each station and to come to some agreement on which processes should be added /changed on the master list of five.
(15 minutes)  

Step 4: Reflection in Groups of Four

Two partner-pairs (4 participants) compare their interpretations of Figure 1, discuss differences and similarities, and prepare to discuss their findings with the larger group.
(30 minutes)  

Step 5: Discussion in Large Group  A chance to negotiate meaning, discuss processes , make changes to the list, and come to agreement (or disagreement) on the meaning of process skills.
(45 minutes)  

Time For the Process Circus
2 1/2 hours 

(listed in Figure 3)  


The Process Circus consists of up to 12 stations set up on tables around the room, each of which has a short and simple activity designed to highlight certain processes. Substitutions may be made to the stations depending on the process /inquiry skills the designers would like to highlight. For larger groups, it is advisable to have duplicate set-ups for each station.  

At each station, leave activity directions (Figure 5) on a card with the appropriate materials. Be sure to number each station so that teachers can keep consistent records about their experiences at each table. Figure 4, a list of stations should accompany participants as they circulate through the stations.  

Ask teachers to work in pairs, as they engage in the activities, discussing and identifying the process/inquiry skills used. Although there will be more than one process for each activity, ask teachers to identify the one or two main process /inquiry skills.

The Activities in Detail:    

Step 1: Setting the Context (10 minutes) 

Provide a brief overview of the goals and value of the Process Circus. Some time should be spent explaining the purpose of the 'Process Circus' activity and its relationship to understanding process skills in classrooms. Reference to the NRC National Science Education Standards, California State Science Framework, The FOSS Program and AAAS Project 2061 Benchmarks process comparisons (Figure 2) is useful.  

Step 2: Doing the Activities (50 minutes) 

Working with a partner, ask participants to visit a station, read the activity direction card and carry out the instructions using the materials provided. The participants' job is to complete the Process Circus Activity Form, indicating which skills are required at each station.  

Partner-pairs do enough of each station/activity to identify the main process skill. They fill in the Activity Form as they do so (see Figure 4 for a separate list of stations). There is no specific sequence of activities that teachers need to follow. We encourage participants to complete all the stations, but sometimes this is impossible. A sampling of seven to eight stations will suffice for productive group discussions later in the session.  

At any given station, participants may be tempted to linger and experiment further --- but make sure that they do the activity as directed and then move on. This restriction ensures that everyone has a common set of experiences for the group dialogue which will follow.   Teachers may wish to add certain process/inquiry skills to the Process Circus Activity Form; ask them to be prepared to explain their rationale for these additions to the group.  

To facilitate later discussions ask participants to write in the name of each numbered station on the Process Circus Activity Form.  

Step 3: Reflection in Partner-Pairs (15 minutes)  

Partner-pairs review their choices on the Activity Form to identify the main processes used in each station and to come to some agreement on which processes should be added/changed on the master list of five. This is a time to reflect and decide upon modifications to the skills listed. Partner-pairs should be ready to explain their choices and modifications.  

Step 4: Reflection in Groups of Four (30 minutes)  

When partner-pairs have finished Step 3, ask each pair to team up with another pair at their table. Ask these groups of four to reflect upon at least three activities to share, compare, and discuss. Partcipants can begin to identify areas for future discussion by comparing points of agreement and disagreement. They can also compare notes about any extra categories they have created, and discuss these in light of the specific activities.  

Distribute Figure 1 (Indicators List) to participants and inform them that they can refer to it to help guide their discussion. Remind participants to be prepared to discuss their ideas with the whole group.  

Step 5: Discussion in Large Group (45 minutes)  

The last part of the Process Circus brings the entire group together to have an unhurried discussion of their experiences doing the activities, their attempts to isolate the appropriate process skills, and areas of disagreement and agreement about potential additions to the list of process skills. The purpose of this last part of the activity is to arrive at some negotiated common understanding around the language of process skills in action. This can be accomplished in a variety of ways. The intent, however, is to have a rich and open discussion in which arriving at a common understanding of process skills takes priority.  

Highlighted below are some of the potential areas of discussion for the group. These points are best made by the participants themselves. You may, however, want to use them as prompts when needed, or as placeholders for future conversations.  

There are many different ways to guide the discussion. One entry point includes choosing one or more challenging activity station for the whole group to analyze, to clarify mutual agreement and disagreement of pertinent process skills. Other areas of discussion can then be addressed by asking participants groups of four to reveal their own questions, areas for discussion, and potential additions to the list. Ask groups to take turns presenting their results, or rely on the group to carry the discussion more freely.  

In either case, activities should be reviewed by all participants and relevant areas for further discussion should be identified by the group. The purpose of the discussion is to arrive at an agreed-upon meaning. It is not necessary to review each activity.  

The different sections below comprise a few of the discussion topics that are most likely to arise within the group. Our experience has shown that the first few items you discuss will take the most time. Meaning will be negotiated, and it will be noted that communicating and observing are part of all activities, then the discussion may move to some of the topics below.    

Discussion Points    

Clarifying And Understanding Processes 

Below we briefly discuss some of the process skills your teachers may have uncovered.   

1. Hypothesizing and Predicting

Some process skills will need considerable time for discussion. For example, the nature of and distinction between predicting and hypothesizing generally requires in-depth conversation as well as reference to actual activities.  

Generally speaking, we think of hypothesizing as providing explanations (based on observation, evidence and past experiences) of an event or phenomenon. Hypotheses typically are plausible but not necessarily correct, consistent with available evidence, suggest a cause or explanation and past experience is brought to bear in their construction. A hypothesis can be tested scientifically; it need not be correct, but it should be reasonable in terms of available evidence and scientific concepts. There may be diverse interpretations of the meaning of the term hypothesis among participants. For this reason, it is very useful to have a full exposition of the variety of commonly used meanings.  

A prediction, which typically is based upon a hypothesis for its formation, also requires evidence, either from the present or past to distinguish it from a mere guess. A prediction tells what will happen in the future or suggests that some- thing will be found that has not been found so far. In Figure 1, prediction is included within the planning category.  

Participants may feel uncomfortable with including prediction within the planning category and may suggest that it have a separate listing along with the five listed in this document. A discussion of criteria for adding prediction is invaluable. And a comparison of predicting with hypothesizing begins to tease out the role of explanation in making hypotheses, and the implicit or explicit role of hypothesis in making predictions.

2. Questioning  

In the Process Circus questioning is not treated as a separate process/inquiry skill, yet other schemata for process/inquiry skills list it as a separate area. Questioning is at the heart of all scientific investigation. For this reason participants may feel more comfortable adding questioning to the original five process/inquiry skills. In either case, a full discussion of pros and cons sheds light on the importance and usefulness of questioning.  

3. Collecting and Measuring Evidence   Because of the importance of collecting and measuring evidence in a fair way participants sometimes suggest that these two functions be added as separate categories. In the Process Circus these are incorporated in the planning category.      


Attitudes Towards Science Up until now we have discussed only the processes of science. During their discussions about processes we find that conversations about attitudes towards science also emerge. Indicators about attitudes towards science are more generalized than attitudes towards process skills. Nevertheless, they are important aspects that can be applied across a wide range of activities rather than to any one activity. Very briefly, these include:


For further reference, at the end of this document we have provided a brief list of texts authored or co-authored by Wynne Harlen.








Process Circus Activity Form

Station/Activity Numbers


Process Skill


















Identify the main process skill for each activity


Figure 1 Indicators of Process /Inquiry Skills in Action

Planning  investigations (including predicting)
Interpreting findings and drawing conclusions
The descriptions below of each skill consist of a list of actions which anyone involved in using the 
process skill may be carrying out.  The items in each list are not in any particular order. 


Planning investigations (including prediction)
Interpreting findings and drawing conclusions


Figure 2 What Are Process Skills?:

A Comparison of Interpretations

There are many different ways of naming and describing Process Skills and no one way is the 'right' one. The following represent examples of different ways to categorize process skills. Together they provide the opportunity to compare systems of representing process skills with different emphases. The National Science Education Standards process skills for grades K-4 include the following:

California State Framework has identified the following major process skills categories:

The FOSS Project's Scientific Thinking Processes

The AAAS Project 2061 describes 'habits of mind' which fulfill a similar role to process skills as ways of thinking and acting in science. In Benchmarks, these are:


Figure 3 Process Skill equipment list

1. Candles

Candle in holder.


2. Dripping Water

10 or 25 ml measuring cylinder.

Watch with second hand.

3. Soils


4. Velcro

Two matching short pieces of velcro.

Hand lens.

5. Hinged Mirror

Two mirrors held vertically with a duct tape hinge.



6. Cartesian Diver

Plastic drink bottle (clear, 1 liter), 90 percent filled with water and with an eye dropper in it containing enough water so that it just floats, then sinks when the bottle sides are squeezed.

7. Ice in Can

Clean empty shiny food can without lid.

Small lumps of ice.

Container to hold ice.

8. Wet Paper

Jar of water.

Several strips of filter paper.

9. Egg in Water

One egg.

Jar of tap water.

Jar of salt water (salty enough to float an egg).


(both water containers must be large enough to get egg out)

10. Toy on Different Surfaces

None, but a clockwork toy can be provided (the point is to plan, not to do).

11. Wind-up Toy

A clockwork toy, preferably slow-moving.

12. Pendulums

A stand with a horizontal arm on which two strings are tied, forming pendulums --- one with a large heavy washer and one with a small light one.

Figure 4 Process Skill station list


1. Candle

2. Dripping Water

3. Soil

4. Velcro

5. Mirrors

6. Diver

7. Ice in can

8. Water and paper

9. Eggs

10. Toy /surface

11. Wind-up toy

12. Pendulums

Figure 5

Process Circus Station Task Instructions

At each station, teachers find one of the following set of instructions written on a card. Their task is to follow the instructions, record the process skills they employed doing the task, and then move on to another station.



Draw what you think the candle will look like when it is lit. Put your labels on your drawing.

Now light the candle.

Draw it again. What is different from what you first drew?




Measure the amount of water that drips from the tap in 30 seconds.

Work out how much water will drip in one day.




If you have three different kinds of soil, how would you find out which had the most water in it?

What kinds of process skills would you use to find the answer to the above question and to describe the investigation you would do?




Put two pieces of velcro together. Try to part them. Try with one reversed/crossways. Make a series of drawings that explain how velcro works.




Place two mirrors at an angle so that reflections of the coin can be seen.

Count the reflections and measure the angle.

Repeal for angles of 30, and 90 degrees.

Can you see a relationship between the number of images you get and the angle between the mirrors? (drawing a graph may help)

Use your results to say how many images you will get at 49 degrees.

See how near you are.




Squeeze the bottle and watch the "diver".

What differences do you see in each diver when the bottle is squeezed?

Try to use these observations to explain how it works.




Put ice part way up in can.

Look at the outside of the can.

Write down as many possible explanations as you can of what you see.

Wipe off the can afterwards before you leave and empty the ice out into original container.




Take a strip of paper and hold it vertically with one end in the water.

Watch what happens for about a minute.

Write down any questions which occur to you as a result of your observations.




Gently lower an egg into the jar of tap water. Notice where it settles.

Take it out and put it into the jar of salt water. Notice where it settles.

Write down an explanation of what happened.




What process skills would it take to fill in the table for an investigation to find out whether the kind of surface on which the toy is put makes a difference too how far it walks.

What will be changed?

What will be kept the same?

What will be measured?

(What process skills would you use to complete this task without having to actually do it?)




On a surface covered with paper a wind-up toy moves 23/4 inches given one turn of the winder. 71/8 inches for two turns and 11 inches for three (Accept these results as if you had obtained them)

Display these results in a form that will help you to predict how far the toy will go for four turns.

(What process skills would you use to complete this task without having to actually do it?)




The two pendulums are of different masses. Use them to see if the mass of the bob makes any difference to how fast a pendulum swings.

Are you entirely happy about the result and the way you found it? If not, suggest ways for improving the investigation so that you would be quite confident about the result.



Harlen, W., Primary Science: Taking the Plunge. Heinemann, 1985, 116pp.

Harlen, W., Environmental Science in the Primary Curriculum (with J. Elstgeest) 1990 London: Paul Chapman Publishing 80pp.

Harlen, W., Progress in Primary Science: Workshop Materials for Teacher Education (with C. Macro, D. Malvern, K. Reed and M. Schilling) 1990, Routledge 200pp.

Harlen, W., Assessing Science in the Primary Classroom : Observing Activities (with S.Cavendish, M. Galton and L. Hargreaves) 1990 London: Paul Chapman Publishing 144pp.

Harlen, W., Assessing Science in the Primary Classroom: Written Tasks (with L. Hargreaves and M. Schilling) 1990 London: Paul Chapman Publishing 144pp.

Harlen, W., Assessing Science in the Primary Classroom: Practical Tasks (with T. Russell) 1990 London: Paul Chapman Publishing 144pp.

Harlen, W., UNESCO Source Book for Science in the Primary School (with Elstgeest) 1992; Paris: UNESCO 272pp.

Harlen, W., Teaching and Learning Primary Science. Second revised edition. 1993 London: Paul Chapman Publishing 209pp.

Harlen, W., The Teaching of Science Second Revised Edition. London: David Fulton, 1996 206pp