HowTo Write A Lab for Emle


With knowledge in elementary school level math, one can design and write an Emle Lab. To create a lab, one combines an existing piece of equipment with newly written instructions.

The lab and instructions are given a number, the same one by convention. You, the lab writer, create an HTML fragment that contains the instructions that the student follows. You also select an existing Emle Equipment which the student will use in the lab. The lab will be the combination of the existing equipment which the student will interact with and the instructions which you write that direct the student in using the equipment. You also need to create a title for the lab.

Here is a summary of what needs to be done:

Lab File

To create a new lab, you use your favorite text editor to create an XML lab file. So for example, if you are going to create lab 1001 you will create a file named emle_lab_1001.xml. You can do this by copying and pasting the content below into your file.

  <lab xmlns="">
    <title>Display A Fraction</title>
      <equipment refid="17" />
      <instructions refid="1001"/>

Since your lab number will not actually be 1001, just replace the red text with

  1. your choice of new number in two places (1001)
  2. your title (Display A Fraction)
  3. the existing equipment number your have selected (17)
using your values instead. This covers the lab creation step.

Instructions File

The part that requires more time is writing the text that the students will follow in using your newly created lab. Again, use your favorite text editor--this time to create the a second file, the instruction document. For lab number 1001 the instruction file is named: emle_instructions_1001.xml. In your case you will not use 1001 but rather the same number in instruction file name as you used for your lab file number.

In this file place an HTML fragment using Emle message elements instead of the English text within an Emle instructions element. By convention the message ids are named instructions-xxxx-yy where xxxx is the lab/instruction number and yy is the message number within the specific lab.

So, here is an example:

<emle:instructions xmlns:emle=""

<h4><emle:msg refmid="instructions-1001-1"/></h4>

<emle:msg refmid="instructions-1001-2"/>


Message Catalog File

Then you add the English text of the instructions to the message catalog file for English (emle_lang_en.xml).

<messages xmlns="" dir="ltr">
<m id="instructions-1001-1">Overview</m>
<m id="instructions-1001-2">It is rather intuitive that <kbd>3/4</kbd> is greater than
<kbd>2/4</kbd>, but it can be very confusing that <kbd>1/5</kbd> is greater than <kbd>1/6</kbd>.
This lab will assist in visualizing that reality.</m>

Your instructions document would have instructions telling the student what actions to take in completing the lab. These would include the math concepts you are conveying in addition to details on correctly using the specific piece of Emle equipment.


When you pick a lab number you must select one that has not already been used for an existing Emle Lab.