Osmosis
Time		This exercise takes approximately 2 hours.
Objectives			Once you have completed this knowledge mapping exercise, you should be able to:
		1.	Have a deeper understanding of the biology concepts in lessons 1.4 (Basic Processes) and 1.5 (Osmosis).
		2.	Identify masked concepts based upon their relations to other concepts.
		3.	Know how to evaluate and polish a semantic network.
		4.	Identify the features of a well-developed concept.
		5.	Construct some well-developed concepts and link them to ideas in the network.
Exercise 1		Concept Identification Game
To Do		1.	Organize yourselves into Groups of four students each. In each Group, form two Teams of two people each.
		2.	Each Group of four students should gather around a Macintosh computer to look at the semantic network entitled '1.5d1 Osmosis Game'. Double-click on the file if it is not already open.
To Do		3.	Select Mask Central from the Concept menu. This will cover up the central concept.
		4.	Select Preferences from the Edit menu. Check to see if there is an 'x' in the box called Ask before Unmasking. If there is no 'x' there, click on the box once and an 'x' will appear. Click on the Set button.
		Figure 1. Preferences dialog on Edit menu.
		5.	You are now ready to begin playing the game. The two teams will take turns identifying the masked concepts. Team A will go first. Select Random Jump from the Move menu. SemNet will move to a new masked concept.
		6.	Team A partners, try to identify the masked concept while Team B watches without helping (time limit about one minute). When you think you know what the concept is, click once on the concept. A dialog box will appear in which you can type the name of the concept. Allow Name Completion to help you complete the word or phrase. Click on OK.
		7.	If you typed in the correct response, Name Completion will assist you and the concept will be unmasked. Congratulations. You have earned 2 points for a correct response on the first try.
		8.	If Team A cannot identify the masked concept on the first try, Team B gets a chance. Team B partners can decide on the name for the masked concept that Team A did not know. Enter the name into the dialog.
		9.	If team B typed in the correct response, Name Completion will assist and the concept will be unmasked. Congratulations! Team B has earned 1 point for a correct response on the second try.
		10.	If neither Team identifies the concept, click on the Reveal button to see what it is. In this case, neither Team has earned any points.
		11.	It is Team B's turn. Repeat steps 5 through 10. Continue in this fashion until all 28 concepts have been reviewed. The SemNet software will take you at random to each of the 28 concepts which have 3 or more instances (unless you interrupt the sequence by performing another task). Keep score using Table 1, below, writing down the name of the concept in each case. The maximum score is 56 points. Table 1. Score Card        Concept          Group A     Group B   1.     2.     3.     4.     5.     6.     7.     8.     9.     10.     11.     12.     13.     14.     15.     16.     17.     18.     19.     20.     21.     22.     23.     24.     25.     26.     27.     28.     Total
To Do		12.	Select Do Not Mask Central on the Concept menu. Then close the net called '1.5d1 Osmosis Game' by clicking in the box in the upper left corner of the window.
Exercise 2		Examining and Polishing a Network
Goal		1.	How would you evaluate a semantic network? Here we'll review the kinds of things your teacher will be looking for in your nets. At the same time, we'll clean up this net so you have an idea how to polish your own nets.
Overview		2.	Open the net called '1.5d2 Osmosis Exercise'. The starting point in examining or evaluating a net is to select About Net on the Display menu (Figure 2). Figure 2. About Net, 1.5d2 Osmosis Exercise
To Do		3.	How many of each of the following elements are in the Osmosis exercise? Concepts:   _____ Relations:   _____ Instances:   _____
		4.	What is the ratio of instances to concepts?
		5.	What proportion of concepts participate in three or more instances?
		6.	How many concepts are completely unconnected to the network of ideas in this web (have zero instances)? What are they? You can identify them by looking at Concepts by # of Instances on the Display menu, and going to the bottom of the list.
		7.	One concept, ballgame, is irrelevant and should be deleted. Select it by clicking on it once in the list display and using the key combination commands, command (Apple) - K, followed by command - Y.
		8.	Two concepts could be connected to the net. Double-click on surface tension in the list display. This will move you to surface tension in the graphic display. Describe the idea of surface tension. Our first connections would be surface tension characteristic of liquid water surface tension characteristic of water Add other instances to describe what surface tension is and what mechanism produces it. Use existing relations as much as possible. Review the list of concepts and make all relevant connections to them. Repeat this process for the remaining unconnected concept, liquid.
		9.	Check the relations in creation order (Display menu). Two relations have the default "inverse of" in the name of the second relation ray, which means that the second relation ray was not properly named. Double-click on each of these relations and name them correctly.
		10.	Finally, go through the net and try to elaborate upon the description of each idea. See the next section for further details.
Exercise 3		Elaborating on the Net
To Do		1.	Close the '1.5d2 Osmosis Exercise' and open the '1.5d1 Osmosis Game' net again. Work with your group to add 6 concepts to the net. The first three concepts to be added are melting, freezing, and boiling. The second three concepts are your choice. Give a rich, principled description for each concept and connect it to the net in a logical way, taking the hierarchies into consideration.
Background Knowledge		2.	Not all of the ideas (such as fog or freezing) in the net were covered in the lab. However, they are familiar in our everyday lives, and we encourage building links between classroom knowledge and personal knowledge.
To Do		3.	We'll help you get started. For example, supposing you want to begin with the instance, 'process has type melting'. Use the Jump command on the Move menu to move to the concept, process. Open the Create an Instance dialog. Then place your cursor on the Down arrow, hold the mouse button down, and scroll down the list until you have selected the relation, has type. Let your mouse button up and the relation will appear in the center box. Tab to the lower box and type 'melting'. Click on OK. You have now connected a new concept to the net.
		4.	If you wish to create a new relation, you do so as follows. Supposing we create the connection, 'melting caused by heating'. Move to melting by double-clicking on that concept, making it a central concept. Then select Create from the Instance menu, type 'caused by' in the center relation box, tab to the lower related concept box and type 'heating'. Then click on OK. We use 'caused by' instead of 'is caused by' for the following reason. It is useful to omit the 'is' or 'are' from the verb phrase, because the verb then seems OK with both singular and plural nouns.
To Do		5.	SemNet will take you to another dialog, the Create a Relation dialog (Figure 6). Is 'caused by' an asymmetric relation (requiring different words in each direction) or a symmetric one (using the same words in both directions)? If you said asymmetric, you are correct. This is the default setting, so you don't need to change it.
		6.	The next decision is whether the relation should be vertical (hierarchical) or horizontal (flows and causal relations). This is a causal relation, so click on the radial button for horizontal (Figure 7). The white areas indicate where the arrows should point. You can over-ride these recommendations, but it is good to follow them in most cases. They are important when you extract a hierarchy from a network.
Figure 6. Initial state of Create a Relation dialog, 1.5d1 Osmosis Game. Figure 7. Suggested changes in the Create a Relation Dialog.
		7.	SemNet initially displayed 'caused by' in the lower box and 'inverse of caused by' in the upper box. With reactions, flows, causality and other horizontal relations, we want to read the active verb from left to right. Thus, change the relation ray name in the lower box to 'causes' and click on 3 o'clock. In the upper box, first press delete to eliminate the highlighted 'inverse of', then leave the relation ray name as 'caused by'. Set the upper clock at 9. Click on OK. The relation is: heating causes melting melting caused by  heating
To Do		8.	It is IMPERATIVE that you think through every instance in both directions, either by saying it aloud or to yourself or by writing it down as we did here. This is the only way to be sure and name the relation properly in the other direction.
		9.	Continue developing your description of melting in this manner and add your other five ideas in the same manner.