How this exercise works

This exercise contains a number of marked sections known as 'gaps'.

It also contains a table of options that can can be put into the gaps. Options can be text, images or any combination of these.

In some exercises there will be a unique option for each gap (a 'one-to-one correspondence'). In others there may be more or fewer options than there are gaps. Options my be shown as 'used-up' when a certain limit has been reached.

You can select gaps and choose options using the mouse or the keyboard.

Using the mouse

• Click on an option to 'pick it up'.
  
  The option will be attached to the cursor.
  
• Click on the gap in which you want to put the option.
  
  The option will be inserted into the gap. If there is already an option in that gap it will be returned to the table.
  
• If the cursor is 'carrying' an option, clicking outside a gap or anywhere on the table will return that option to the table.
• If the cursor is not 'carrying' an option, clicking on a gap already containing an option will pick up the option.
  
  
  You can then click on a gap to insert it into that gap,
  
  
  or click outside the gap to return it to the table.
• If you want to transfer the contents of one gap into another gap just click on the first gap to pick up its contents,
  
  
  then click on the second gap to replace its current contents with those of the first gap.
  
  
  The previous contents of the second gap will be returned to the table.
• You can put options in gaps in any sequence you want, and revisit and change gaps that are not already marked as correct. There are exceptions to this behavior: see the section 'Free and forced sequence' below for further details.
• When you have completed all the gaps (or as many as you can) click on the 'Evaluate' button in the control panel. See the section 'Evaluation' below for further details about the evaluation process.

Using the keyboard

In this exercise you can select gaps, set their options and evaluate your answers using the keyboard.

• You can see a list of the keys that are available and their functions in the control panel.
• Some keys enable you to move from gap to gap in the exercise. The currently selected gap is marked in yellow.
• Some keys enable you to move from option to option in the table. The currently selected option is marked in yellow.
• Some keys put the selected option into the currently selected gap.

Evaluation

There will usually be a limit set to the number of attempts you can make to get the answers correct in an exercise. This number is shown in the 'Number of attempts allowed' field just above the 'Evaluate' button.

• The evaluation process checks whether you have selected the correct option in each gap and marks the gap accordingly.
• If there are any gaps with incorrect options — and you still have some attempts left — you will be invited to try again to set the correct option in each incorrect gap. You can't change correct answers.
• If there are no attempts left and there are still incorrect options in any of the gaps, the correct options will be put into these gaps.
• Gaps are marked in different colours to show whether the answer was correct first time, correct after one or more attempts, or corrected after all attempts had been used up.
• If you have made mistakes try to understand why your answers were incorrect and repeat the exercise. You can do this easily by clicking the 'Restart' button on the control panel.

Free and forced sequence

In most exercises you can work through the gaps in any order. Each evaluation applies to all the gaps, as does the number of attempts you can make to get the exercise correct.

In certain exercises — mathematical expressions, for example — the answer to one gap may depend on the answer to a previous gap. Such exercises will not allow you to select freely the order in which you input the answers.

In these cases each gap has to be evaluated individually. The number of attempts allowed is now the number of attempts you have for each gap, not the exercise as a whole.