Abstract: Students are given the opportunity to identify, describe and predict how erosion and deposition affect the landscape of Isle Royale using a topographic map. A discussion comparing selection based assessment and constructed response assessment and the use of rubrics is included.

It is common for teachers to evaluate student understanding either by selected-response (e.g., multiple choice) or by using constructed response. In McTighe and Ferrara's, Assessing Learning In The Classroom, (McTighe and Ferrara 2000) a constructed response is when students have to create a product or construct a response to a question to show what they understand. An example of a constructed response would be a fill-in-the word, a short answer question or making a concept map. Performance based assessment is actually comprised of three categories which include creating a product. Examples of this assessment type include writing an essay or designing and investigating a science project, completing a performance similar but not excluded to an enactment or debate and finally process-focused, such as oral questioning or an interview (McTighe and Ferrara 2000).

There are advantages to using either form of assessment however, there are also limitations. Selected response assessment does allow the teacher to examine the process skills of critical thinking, creativity and oral communication (McTighe and Ferrara 2000). Test questions like true and false or vocabulary matching, which are forms of selective assessment, tend to access knowledge that is out of context and not in meaningful “real world” situations (McTighe and Ferrara 2000). I want to provide my students with the opportunity to demonstrate their understanding of erosion and deposition using an actual example of something to which they can relate. My assessment uses a topographic map of Isle Royale, a national park found within relatively close proximity to my students' homes. Students are asked to identify various erosional landforms and describe the Earth processes involved in their creation. This is a very practical assessment because it is not uncommon for some of my students to use topographical maps to hunt or for recreational purposes.

Authentic assessment is performance-based assessment where the student demonstrates what they understand by applying knowledge in a “real world” context (Wiggins pp.41-47). Since scientific knowledge is gained by connecting a new idea to a previous one, every child's experiences regarding a scientific concept are personalized (Rutherford and Ahlgren 1990). This translates into answers on a performance-based assessment that are not identical to the teachers' answer key. Sometimes there is not one-single correct answer to a real world problem. This is one of the truths and limitations to this type of assessment. Because of this limitation, the teacher must use judgment-based evaluations which takes time and introduces the problems of scoring reliability and fairness (McTighe and Ferrara 2000). One way to compensate for the possible ambiguity in scoring is to use a tool referred to as a rubric.

A rubric consists of a table that has examples of the criteria used in the score obtained in a constructed response scenario. According to McTighe and Ferrara p. 15, “ Rubrics consist of a fixed measurement scale (e.g., four-point) and a list of criteria that describe the characteristics for each score point. Rubrics are frequently accompanied by representative example of student products or performances that illustrate each of the points on the scale.” I have learned to appreciate the use of rubrics because they provide my students with the guidance needed to produce quality work. Students need examples of expected learning outcomes and they need the freedom to creatively express what they understand in a “real world” situation if I want a true evaluation of conceptual understanding . An example of the rubric used in my assessment is found in Figure One.

The assessment used in the erosion and depositional unit consists of three parts. The first requires students to look at a topographical map of Isle Royale. While looking at the map, students will identify various landforms found on the island and determine whether the landform is an erosional or depositional feature. Next, they need to explain the process which created the landform. The second part of the assessment asks students to make a drawing of the island as it is currently, as it may be after 1000 years and then again after 5000 years. This allows me to observe whether the student understands how time is involved in geologic processes like erosion and deposition. The third part of the assessment is for the student to locate three different erosional features within Hancock, Michigan, or the surrounding area. Students will have to draw the feature and write a description of the feature as well as describe how it formed.

Each part of the constructed response assessment has a specific purpose and is connected to an activity previously conducted in class. Just prior to completing the assessment, students were required to view a web site containing many links showing topographical maps. The contour lines changed with respect to the landform described.

It is a goal that my students take the topography experience and apply their knowledge gained from the erosion and depositional laboratory activities, readings and discussions, to identify and explain the erosional landforms found on Isle Royale, around themselves and the world!

Table	10 points	8 points	5 points	0 points
Table	Lists 10 different landforms with a row including the erosional/depostional force creating it . Also has a row with a brief desription of the process creating the landform. Very neat .	Lists 7-10 landforms with the erosional/dep. force and has a brief description of the process. Vague descriptions of landform formation. May lack neatness.	Lists 5-10 landforms. Missing some erosional/dep forces and has unclear descriptions of processes involved. May lack neatness.	No table.

Drawing	5 points	3 points		0 points
Drawing	Drawing on a separate piece of paper predicting how the island may appear after 1000 years and again after 5000 yrs. Includes 5 examples of how the landforms have evolved over time. Neat and outlined in color. Clearly labeled with descriptions and predictions.	Drawing on a separate piece of paper predicting how the island may appear after 1000 years and 5000 years. Includes 5-3 examples of how the landforms have evolved over time. Some of the examples are not erosional landforms and/or the student did not clearly explain how the island changed over time. Appears rushed and is missing labels and some predictions.		No drawing
Hancock Erosional and Depositional Features	10 points	8 points	5 points	0 points
Hancock Erosional and Depositional Features	Sheet(s) contain 3 different examples of erosional and/or depostional features found in the Hancock Area. The student has identified the type of landform, described its location, made a sketch and written a paragraph describing the erosional or depositional forces which created it.	Everything is the same as the ten point box except the student has only identified 2 erosional or depostional features or the student has 3 features however, some facts or descriptions are missing.	The student has identified 1-2 landforms but is missing information describing the feature.	No features identified.