You have already selected the Subject that you wish to base your Query on and that you wish the Query to be a Summary one, however the Subject may contain data Fields that you do not wish to be included in your Query.  The Query Wizard - Select Field form lets you choose which Fields will be included in your Query, and which which of those fields should be used for grouping the data and which of those fields should be used to calculate summaries.

SELECTING FIELDS

The screen displays a List of the fields that are 'Available' for selection, and a list of Fields that you have already selected.  The Fields that have been already selected are divided by into two lists. The Group by list and the Summarize list.

To select a Field to group by, first highlight it by Clicking on it in the Available list, and then click on the top '>>' button to move it over to the Group by list.

To select a Field to summarize by, first highlight it by Clicking on it in the Available list, and then click on the bottom '>>' button to move it over to the Summarize list.

You can select the type of summary to be used for the highlighted Summary Field by using the Summary Type drop down list.

Depending on the data type of the highlight Summary Field different items will be available in the Summary Type drop down. For example numeric fields will have Sum, Maximum, Minimum, Average, Count, Distinct Count, First and Last but non numeric fields will only have Count, Distinct Count, First and Last.

You can also use the box immediately above the list of Available Fields to enter part of the Field name that you are wanting to Add. As you type in this box you will notice that the list of Available Fields will be filtered based on the what you have typed. This is a useful way of searching for the field you want if there is a large number of Fields in the Subject you are using for this Query.

REMOVING FIELDS

To remove a Group Field, first highlight it by Clicking on it in the Group by list, and then click on the top '<<' button.

To remove a Summary Field, first highlight it by Clicking on it in the Summarize list, and then click on the bottom '<<' button.

SUMMARY GROUP OPTIONS

You can set Summary Group Options for the highlighted field in the Group by list by clicking on the Group Options button. More details on Summary Group Options can be found in the Summary Group Options topic here.

DATA PREVIEW

You can also right click on any of the fields displayed in either the Available Fields, Group by or Summarize lists and a pop up menu will appear. This gives options for adding or removing fields from each of the list but it also gives you the option to preview some of the data in the Data Preview screen.

Once you have finished making your selections click on the 'Next >' button to move on to the Query Wizard - Sort Criteria form.