Over a period of five years, we observed seven different teachers using simulations in their science classes at the middle and high school level. At the start of the project, many of the teachers we observed reported that they saw simulations only as a way to present a final, expert, scientific model to their students at the end of a lesson. However, we observed other teachers using simulations differently. Teachers began adopting some of each others strategies and we noticed they were more frequently using simulations to increase student engagement and to support student reasoning and learning. When asked to reflect on their experiences, many of the teachers reported feeling that their ideas about using simulations had shifted. They now saw simulations as a powerful tool that could be used at additional points in a lesson to promote student thinking, not just as a way to present a final model. In this manual, we will highlight different ways simulations can be used over the course of a lesson and present some of the many strategies we saw teachers employ to increase the impact of simulation-based lessons.

We observed teachers using simulations in varied ways to support different stages of a lesson unit. Some teachers, for example, used simulations when introducing a new concept. In one strategy we observed at this stage, a number of teachers projected in front of the class a "frozen" (Paused) simulation depicting the target concept and asked students to predict what would happen when they pressed Play. This strategy served to help students become invested in what they were seeing and to promote visualization and model construction--two topics we will discuss further in this manual. We also saw teachers using simulations later in their lessons after the target concepts had been introduced and discussed. In a strategy we observed at this later stage, a number of teachers used simulations to project discrepant events, events that called into question the mental models students had of a given concept. Used in this way, the simulation served to stimulate student reasoning and to prompt them to evaluate and modify their mental models. These are only two of many ways we saw teachers creatively using simulations to promote reasoning and conceptual change at a variety of points in their lessons.

Our assumptions about goals of instruction. We should state some of our assumptions here: We assume that:

• The teacher is interested in fostering conceptual understanding; the new concepts should "make sense" to students.
• An important part of doing this is to foster student active thinking.
• Qualitative models are of central importance in science learning (in addition to their mathematical counterparts where appropriate). That is, we assume that teachers are interested in students being able to explain why observed phenomena occur as well as knowing about the phenomena themselves. (Conceptual understanding is a part of this.) This means that teachers push students to give explanations.
• Many of our strategies are for using a simulation in front of the class. For these we assume the teacher will have capability to display simulations via a video projector or large monitor.

For incidental logistical reasons, most of the video examples we have and display here are from whole class mode. Some teachers may assume that simulations should always be used in small group mode if possible. However, there may be advantages to each mode, and we encourage teachers to try each mode and to think about the advantages of each. A recent study of matched sets of high school physics classes [2][3] found that contrary to the teachers' expectations, no evidence was found in pre-post tests for an advantage for students in the small group mode. Instead, a slight trend was observed in favor of the whole class condition.

This means being able to entertain, temporarily, students voicing nonstandard ideas and theories so that student thinking is aired and examined. There are major benefits of this, including the teacher gaining feedback on the current level of understanding in the class, and therefore insights into the many conceptual pieces that need to be learned; students becoming engaged in reasoning and making sense of concepts; students learning to evaluate models and theories with the help of the teacher; students coming to see science learning as a process of model generation, evaluation, and modification, rather than as a process of rote memorization.

However, many teachers find that initially they need to work at staying neutral during such discussions, and need to learn some techniques for fostering this kind of discussion. One of the best resources we know of  concerning the above assumptions--and for teaching strategies to foster discussion in general--is the website by Mark Windschitl and colleagues, "Tools 4 teaching science" (in particular the following papers and examples: "Big Idea Primer", "Discourse Primer", and Video examples of drawing out student ideas).

This present manual site extends the topic of discussion-leading strategies to include the use of Simulations and Animations. Incorporating these into discussion requires additional teaching strategies. Many researchers believe that exemplary teaching occupies a 'middle ground' where open discussion of ideas is strongly encouraged, but where the teacher also regularly guides the discussion toward target concepts. This manual focuses most on strategies for orienting and guiding discussions while assuming that the teacher is also promoting an open exchange of ideas. If both of these occur one can see a kind of 'co-construction' of target ideas where some of the ideas come from the students and others come from the teacher so that with successive additions and modifications of student ideas target models become understood and appreciated.

In addition to observing new and apparently powerful uses for simulations in middle and high school science lessons, we also observed a number of themes surfacing repeatedly in our analyses of the lessons we observed and in the teachers’ reflections on their experiences with the lessons. One of these recurring themes was the importance of supporting students’ interactions with the simulations. Previous research by Lowe [4] suggests that students may not always attend to the most important features of a visual presentation, and even when they do, they may misinterpret what they are viewing. In the manual we highlight a number of strategies designed to help students interpret what they see in a simulation whether used in a whole class or small group format. We also recommend periodically checking in to confirm that students are interpreting the visual input as intended. Teachers can do this by asking students to write, draw, or describe what the simulation represents. We also saw teachers altering the way they presented the simulation to their classes to simplify the visual presentation, decreasing distractions, and increasing focus on the most important features and visual relationships. Finally, one teacher recommended simply giving students enough time to process what they see in a simulation. This may mean running it slower or leaving it up longer. A richer description of these and other strategies for supporting student interpretation of the visual input can be found within the core and additional strategies in this manual.

Another reoccurring theme in both the teacher feedback and our classroom observations was the idea that, even when they are interpreting the simulation with accuracy, the use of simulations alone is not sufficient to increase student engagement and support conceptual change. The teacher plays a key role in shaping the lesson around the simulation in a way that encourages active engagement with the concepts being presented. Supporting effective classroom discussions is one way to do this, as indicated above. As a result, we present a number of strategies we observed teachers using to promote student engagement and to inspire active reasoning during both whole class and small group discussions during simulation-based classes. Designing effective worksheets to guide their interactions with the simulation by asking provocative questions and providing clear directions is another strategy teachers can use to support student reasoning about the target concepts. Finally, we offer a number of wrap-up strategies teachers can use at the end of a lesson or unit to ensure that students have a scientifically accurate understanding of the target concept that they can apply and generalize to novel problems.

The teachers we observed found it useful to familiarize themselves with the simulations before presenting them in a classroom setting. This not only allowed them to become fluent with the simulation controls but also to identify features of the simulations they wanted to highlight in their lessons. By working with a simulation ahead of time, teachers also found that they were able to identify both the unique strengths and the limitations of the simulations they had chosen.