1. Write a brief memo to Tammy explaining the importance of data validation during the input process.
Students should understand that when it comes to data validation, an ounce of prevention is worth a pound of cure. A data validation check improves input quality by testing the data and rejecting any entry that fails to meet specified conditions. Responses should point out that the best defense against incorrect data is to identify and correct errors by using data validation checks before they enter the system.

2. Suggest at least three specific data validation checks that might help reduce input errors.
Students can suggest at least eight types of data validation checks into the input process.
a) Sequence checks, which are used when the data must be in some predetermined sequence.
b) Existence checks, which are used for mandatory data items such as Social Security number.
c) Data type checks, which test to ensure that a data item fits the required data type, such as numeric or alphabetic.
d) Range checks, which test data items to verify that they fall between a specified minimum and maximum value.
e) Reasonableness checks, which identify values that are questionable, but not necessarily wrong.
f) Validity checks, which are used for data items that must have certain specified values.
g) Combination checks, which are performed on two or more fields to ensure that they are consistent or reasonable when considered together.
h) Batch controls, which are totals used to verify batch input. Batch controls might check data items such as record counts and numeric field totals.