August 11, 2012
Input controls are fail safes that ensure that data is entered correctly, completely, and securely, in order to complete forms. As a systems analyst, one must focus on input control in every step of input design. There are many types of input control that can be implemented during the design process; all of which have a function necessary to maintain the integrity of the transaction. To list all of the input controls would take forever, so we will cover four in the following paragraphs.
One type of input control is the standard text box. The text box can display messages or provide a place for the user to enter data. The text box is used when the system requires the user to type information such as city names, airport codes, or web page addresses. When using a text box, it is often helpful to use an auto complete function to help ensure proper data entry. This would be beneficial when the number of choices are too numerous to be displayed in a drop down list box. The data integrity error that is possible from using a text box is almost always going to occur due to human error. If the text box is programmed to accept letters (i.e. Name) and the user inserts a number, this will result in a data integrity error.
Another type of input control is the previously mentioned drop-down list box. “The drop- down list box displays the current selection; when the user clicks the arrow, a list of the available choices displays.” (Shelly & Rosenblatt, 2012) This input control method is used when there are only a specific number of choices to be made. A common example for the drop-down list is when a user is being asked in which state they reside. There are fifty choices, and these are the only options that are acceptable answers to the inquiry. If this input control method was not in place, there could be a multitude of things entered in this block that have nothing to do with state of residence. This would end in a data integrity error because the user entered information that had nothing to do with the question asked. Presenting the user with a set number of choices ensures that the data entered will be proper. The data could still be entered incorrectly due to “fat fingering” the mouse, but it will at least be in the correct format.
The calendar control is an input control option that allows the user to select a date that the system will use as a field. This option is very common when making online reservations. The user is shown a picture of a calendar and given the option to change the month and sometimes year. The user will click the date on the calendar that they wish to use for their reservation and this information is saved in the system. If the dates are not available, they are often grayed out and not clickable. If the calendar control was not in place, users could make reservations for nights that were already booked. They could also enter dates incorrectly and be approved for those reservations, yet think that they entered the information correctly. The break down in data integrity would be almost inevitable, due to the sheer number of users making reservations at a hotel or restaurant on any given day.
The final input control option that we will cover is the radio button. The radio button, or option button, represents one choice in a set of options. They allow only one choice to be made out of a given list. Once the button is clicked, a black dot will fill the circle identifying the chosen option. If a user chooses a different option, that circle will be filled with a black dot and the previous choice will be removed; when one button is switched on, the others are switched off. An example of when to use the radio button would be choosing a male or female when the user’s sex is requested. If the user clicks the radio button labeled “Male”, he cannot change to “Female” without the system automatically removing the...