Every year my students come to class with the idea that it’s colder in the winter because the earth is farther away from the sun. Where did they get this idea?
—Lauren, Aurora, Illinois
Along with notebooks and pencils, students bring some common misconceptions to science class. It’s hard to tell where students learn these misconceptions: from their friends, parents, television, movies, or other media. (I wonder, could the Flintstones be the source of the misconception that humans and dinosaurs lived at the same time?) Perhaps they hear only part of an explanation and invent the rest.
Your students are not unusual — the misconception about the seasons is pervasive. Years ago, there was a study of college graduates who also could not describe the reasons for the seasons (described in the video A Private Universe).
Many textbooks show the earth’s orbit as an exaggerated ellipse, and students know that if they sit closer to a heater they feel warmer. And so, the earth must be closer in its orbit to the sun in the summer when it’s warm (or so they think). They may not realize that their ideas are incorrect, and simply telling the students that their ideas are wrong won’t help them learn the correct ones. Even if students recognize that the earth’s axis is tilted, they may not see the connection between this tilt, the seasons, and the length of daylight time we have. For some additional resources (including visuals) for teaching this concept, go to NSTA’s SciLinks and use “season” as a keyword to get a list of related websites.
If learning involves building on our current understanding, then finding out what students know, don’t know, or think they know is important at the start of a unit. A written pretest might help, but students may have just memorized some facts or definitions without really understanding a concept. I’d recommend the types of activities in Uncovering Student Ideas in Science, by Page Keeley, Francis Eberle, and Lynn Farrin (published by NSTA Press ). The book has formative assessment “probes” to use prior to and during instruction. They are designed to have students apply what they know (or think they know) to a situation. For each probe there is a summary of the topic, a detailed description of what can be learned from the students’ responses, teaching suggestions, and a list of resources on the topic. These probes are in the form of questions or activities that could also serve as engaging activities (or “hooks”) at the beginning of a unit. There are three volumes in the series, each with 25 probes covering a wide variety of topics.
Every year that I taught life science, I had to contend with three big misconceptions: insects are not really animals, the blood in our veins is blue, and plants use minerals from the soil as food. Textbooks often show diagrams of the circulatory system with the veins colored blue, and commercials on television talk about fertilizer as “plant food.” But I still haven’t figured out the source of the insect misconception.

Two particularly inquisitive and bright former preK students (siblings) unexpectedly attended a workshop I gave for early childhood teachers about bringing local butterflies into the classroom for observation. Instead of distracting from the planned workshop, they added to it and made me look good! It was gratifying to have them model how to ask questions, and to comment on what they had learned, one and three years ago, respectively. They recalled the words “pupa” and “chrysalis” and remembered how they saw a red liquid (miconium) after the butterflies emerged from their chrysalides and that it wasn’t blood. It was inspiring to see how observing part of the butterfly life cycle made a great impression.
I hope that all students remember as much from that experience. Repeat the life cycle observations with other species of butterflies or Tenebrio beetles (mealworms) and children will observe insect metamorphosis, and relationship between animal and food source, more than once.
To enable all students to make observations, teachers adapt activities to the needs of the students. Have a bright light source in the classroom to help children with low vision see details. Put caterpillars or other small animals in small containers such as medicine bottles so children with fine motor control difficulty can hold them without accidently squishing them. Some teachers set aside a time for drawing or otherwise documenting an observation of nature each day. What do you do in your classroom to make sure that all students get to carefully observe?
Peggy

I see that NSTA has just published the Tool Kit for Teaching Evolution by Judy Elgin Jensen.
According to its description,
Teaching evolution is part of the core biology curriculum, and this new resource provides a teacher-ready summary of the scientific, legal, and ethical talking points for discussion of the topic. Compiled by NSTA with input from the National Center for Science Education, the NSTA Tool Kit for Teaching Evolution pulls together historical facts, scientific data, legal precedent, and other invaluable information for answering the all-too-common question of “Why teach evolution?” Biology and life science teachers will appreciate this resource, complete with classroom activities, for its ability to help you cover a relevant issue with depth and pedagogical support.
This is a very powerful resource that should be on the bookshelf of every science teacher, whether or not you teach biology. Did I say “bookshelf”? Of course you can order a hard copy, but as an NSTA member, you can download a PDF version as a free (free!) e-book for your virtual bookshelf.
The book suggests a variety of print and on-line resources, including SciLinks keywords: evolution teaching resources, evolution, history of evolution, Darwin, genome research, speciation, phylogenetic trees, antibiotic resistance, and human evolution.
For additional resources on the teaching of evolution, check out a previous blog entry on Evolution with some of my favorite sites.

Science activities that children initiate motivate teachers to extend and expand the activity. Children learn more details about their area of interest and make connections with other concepts when they work more than once on activities about the same concept, such as mixing colors. If you see a child noticing colors mixing at the easel, offer to bring out additional materials to explore color mixing.
See the October Early Years column, Color Investigations in Science and Children (NSTA membership required) to read about additional coloring mixing activitities.
When an activity is both easy to prepare and easy to clean up, teachers are more likely to see that it happens, and to encourage the children to repeat the activity. These two circumstances can come together in activities where children are mixing and separating colors with a variety of materials. Colored acetate (sold as clear wrapping paper in party stores) is dry, easy to store, and easy for children to handle over and over again to create new colors when they overlap the squares of color.
Mixing paint need not be messy if tiny spoonfuls are served onto a plate, mixed with a single finger, pressed with a paper towel or sheet of paper to record the colors achieved, and then washed off the plate to begin again. The young scientists repeat the process, discuss their procedures with each other, and record their results. Don’t worry that you are stifling their work by using small amounts on occasion. Children enjoy changes in scale, going small and going big!
In collaboration with their students, teachers discover new ways to explore familiar concepts. Tell about your color explorations in a comment so we can all learn.
Peggy

I want to use more essay-type questions on my unit assessments, but with 150 students I feel swamped trying to grade all of the papers and provide feedback. Any suggestions for making this a good learning process?
—Brian, Reading, Pennsylvania
I can feel your pain, sitting at the table for hours after giving a test. But from my experiences, I can offer a few suggestions.
Determine the purpose of your test questions. Making lists and writing definitions are low-level tasks that could be assessed with objective or short-answer questions. Use your time to find out how well students can describe, analyze, summarize, compare/contrast, identify advantages/disadvantages, create a graphic, interpret data, or address what if or why questions.
This means that there is not one correct response. Make a rubric in advance to describe what a satisfactory response would include. Do the same for a great response and for an incomplete one. I used a version of the rubric my state had for writing, with an emphasis on the content of the response.
It may be helpful to have students do more writing in class, where you can model and provide instant feedback. Share some sample questions and your basic rubric with the students ahead of time along with examples of responses at each of the levels. They can practice writing in their notebooks or share their work with each other.
Explain to students that you need time to read their work carefully and respond thoughtfully. I’ve tried dividing the test into two parts: objective and essay. The first I could return and discuss quickly (even the next day), but the essays I returned and discussed a little later. I also had a score for each, showing students the essay part was just as important as the objective questions.
Ask students to start each essay response at the top of a page, even if their previous response did not take up a whole side. You can then organize the papers so that you are reading all question 1s, then all question 2s, and so on. This way your rubric for each question is fresh in your mind, and after a few papers, you get the general gist of the responses.
Now that you’re streamlining the process, you should have time to provide feedback. Feedback should be more than a final grade or total score and more than a generic “good job” or “needs work.” To be effective, feedback should be focused on the task to provide comments on what was good and suggestions for improvement. I’d recommend a new book from the Association for Supervision and Curriculum Development How to Give Effective Feedback to Your Students. The January 2008 issue of Science Scope had “Assessments” as a theme with ideas for feedback, too.
If you teach more than one subject, don’t give tests to all of your classes on the same day. Give yourself some breathing room.
Most importantly, don’t give up! In real life, few of us take multiple-choice tests for a living. But we do write notes, memos, summaries, letters, articles, and blogs. So anything we can do to help students become better thinkers and writers is worth the time and effort.

For an activity to explore buoyancy—what materials and which objects sink or float in water—I gave each child in a small group an object to hold. Then I explained that we were going to think about the objects and say where we think they will come to rest in a big tub of water—at the bottom or near the top of the water—BEFORE we put the objects in the water. Most of the two-year-olds are in the “thought is action” stage and immediately dropped (threw, in some cases) the objects in the tub. “I think it’s going to…It’s floating!”
The four-year-olds seemed to savor their anticipation of “doing”. They took their time to tell where they thought the object would come to rest before testing their prediction. It’s wonderful to work with children who are not afraid to be “wrong”. My hope is that I do nothing to change that.
Pumpkins are fun objects to use in this activity. Children often predict that the largest one will sink, even after witnessing the smallest and the medium pumpkins floating. Children can record their results by drawing the pumpkin shape on a teacher-made template of the tub.
Some children may notice and explore the effect of magnification, especially if the tub you use is round.
Read the October Teaching Through Tradebooks column, Pumpkins! By Karen Ansberry and Emily Morgan for more pumpkin exploration (grades K-6) with literature connections to How Many Seeds in a Pumpkin? by Margaret McNamara and Pumpkin Circle by George Levenson.
Peggy