On this page you will find detailed instructions on how to create a simple decision-making calculator using the online software LinkNotions.

## Example of the decision to buy a share

We have chosen to take the example of the decision to buy a share, but you can easily adapt it to other decision-making : all types of investments, increase in stocks, start-up of a cooling system, …

You can then create your own decision-making calculator. You will use your own criteria and you will formulate the conditions for their application with the weights that you consider appropriate for the type of decision you need to make.

Let’s start.

We assume that you have no knowledge of LinkNotions software. If you have, you can skip a number of explanations.

2. Create a diagram : In your account click “Create diagram” (1). In the window that opens, enter the name of the diagram as well as the number of columns (Width: 3) and the number of rows (Height: 2). Click “Create”: The diagram is open.

3. Create notions : Place the cursor on the empty square in A1. It turns blue. Double-click the square. Enter the name “Share price” in the window that opens (2). Click “Create” (3). The notion “Share price” is created in A1 (4).

4. Give values to the notions : Click the notion A1, then click on the button “Show / Hide the calculation bar” (5). The “calculations” window is open (6).

Enter “10” with your keyboard. The number 10 is written in the “Main expression” field (7). Then click the “Save and Calculate” button (8) (or type Enter or click any place in the diagram). You now see that the notion “Share price” has the value 10 (9).

Proceed in the same way to create the notion “Nominal value of the share” in B1 and assign it the value 20 (10).

5. Calculate the value of a notion using a formula :

Create the notion “Ratio: Price / Nominal value” in A2 (11). Click the notion to activate its calculation window. The value of the notion B1 is calculated according to the notions A1 and B1. In fact: A2 = A1 / B1.

We could write the formula A1 / B1 in the “Main expression” field and the result would be correct. But referencing a notion by its position is dangerous, because the formula is no longer exact as soon as you move one of the notions referenced in the formula. It is more prudent to use the id-number of the notion referred. You will find the id-number of the notion B1 in the tooltip (12) by placing the cursor on the notion. You can also find the id-number of the activated notion (A2) in the Info window (bottom right of the screen) (13). The id-number always begins with the two letters id.

The id-number for A1 is id1. The id-number for B1 is id3. The formula to be entered is therefore id1/id3 (14). Click “Return” and the result 0.5 is displayed in the  notion “Ratio: …” (15).

### 6. Calculate the purchase decision :

Now let’s take a look at the notion “Purchasing decision”. We create it in A3 (16). This notion must display the purchase decision.

We selected a sample of 4 recommendations according to the value of the “Price / nominal value” ratio (A2).

• – purchase highly recommended (if the ratio is less than 0.35)
• – recommended purchase (if the ratio is between 0.35 and <0.8)
• – purchase not recommended (if the ratio is between 0.8 and <1.2)
• – purchase strongly discouraged (if the ratio is greater than 1.2)

We must therefore transpose these “displays” and their respective conditions in the “Calculations” window. It’s quite easy!

As there are 4 displays, we must add three by clicking 3 times on the “+” behind “Condition” (18bis).

We now write the 4 displays (17) and their respective conditions (18).

Warning:

the displayed text must be enclosed in quotes. !!!

the comma must be written using a point !!!

• – purchase highly recommended (condition: id6 <0.35)
• – recommended purchase (condition: id6 <0.8)
• – purchase not recommended (condition: id6 <1,2)
• – purchase strongly discouraged ()

The software reads the instructions as follows:

• – purchase highly recommended if id6 <0.35
• – otherwise: recommended purchase if d6 <0.8
• – otherwise: purchase not recommended if id6 <1.2
• – otherwise: purchase strongly discouraged.

Click on “Save and Calculate” (or type Enter or click any place in the diagram). The display is ” recommended purchase ” since the value of the ratio (0.5) (19) is between 0.35 and 0.6. We see that the text “recommended purchase” just enters the square. As other texts are longer, we will enlarge the squares. Click the “Settings” button (20). The “Workspace settings” window is open (21). Drag the “Width of squares” slider (22) to the right (up to 225). Click “Save” (23). The squares have become larger rectangles.

### Conclusion :

We have presented a very simple example of decision making above.

The decision is the result of a single calculation.

Please find below a more advanced diagram of how to make a decision to buy a share.

You can copy the above diagram in your account and edit it.