Attention Deficit Hyperactivity Disorder (ADHD) is an attention disorder characterized by certain criteria: inattention, hyperactivity, impulsiveness, and extreme disorganization. If you are concerned that you or your child might be suffering from ADHD, one of the most effective diagnostic tools is the Tova ADHD test. "Tova" stands for Test of Variables of Attention, and it is used by psychological professionals the world over for pinpointing the presence and degree of ADHD in a patient. Fortunately, however, you can also take the Tova test for free online.

Visit the Tova website (see Resources below) to retrieve a copy of the Tova ADHD test. This is not the only place where the test is available for free online, but going straight to this site will ensure you're getting an accurate version of the test.

Click on the link to download the Tova ADHD test to your computer. It is at the top of the screen, and it requires that you are running the Windows operating system.

Run the download program from the installation icon on your desktop. This will take you through the steps to download the program in its entirety.

Read the Tova software license agreement and click "I Agree" if you accept the terms and conditions they set forth. If you aren't able to agree, you won't be able to download the program.

Choose the area of your computer in which you would like to store the Tova ADHD test software. The default folder is usually in the C drive. Make sure you check it before you click "next".

Complete the installation, making the appropriate selections. If you've previously downloaded a copy of the Tova ADHD test, you'll be asked if you want to copy those files to continue.

Access the Tova ADHD test from the file in which you installed it. In most cases, an icon will have been created on your desktop.

Check the hardware. TOVA requires specific hardware that must be installed on your computer, including a printer accessed through a port and a sound card that is compatible with their system (if you want to take the auditory test). Pressing F3 will automatically check the hardware and alert you to any problems.

Take the practice test. This will acclimate you to the program and help you learn the controls without pressure. Once you've completed the practice test, you can take the real thing.