Often times, referees will blow the whistle to signal either a foul or a violation.  In order to make this call, you must be able to recognize not only what represents a foul or violation, but what is the appropriate hand signal for each.  Remember, coaches, parents, and players want to know why the whistle was blown. Using proper hand signals is an effective way to communicate what is happening on the court. Below is the definition of a foul and a violation as well as their basic hand signals.

A foul is defined as any illegal contact made between a player and his/her opponent.  A personal foul can be committed by an offensive or defensive player. When a foul is committed, the referee should blow the whistle sharply and raise their fist high in the air above the head. The hand signal that follows details the type of foul that was committed. 

Foul Hand Signal Definitions

Below are the different types of fouls and their proper hand signal:

Hand Check

Using the hands to check the progress of an offensive player when that player is in front of the defender who is using the hands. Signal:  Face one palm away from the body as the other hand grabs the wrist.

Holding

Foul involving grabbing onto the arm hand or wrist of the offensive player. 
Signal:  Hold one arm at a 90-degree angle with fist turned with knuckles facing outward as the other hand grabs the wrist.

Blocking

Illegal contact which impedes the progress of an opponent.  A blocking foul is called when the defender blocks with the body and his/her position is not clearly established.  
Signal:  Place both hands on hips.

Player Control Foul (Offensive Foul)

A foul called when an offensive player runs into a defender who has an established position .  That position is established when the defender gets to the spot first without contact while both feet are touching the floor. Once this position is obtained the defender may move laterally or at an angle or backwards in order to maintain this position.
Signal:  Place one hand behind the head at a 90-degree angle.

Pushing

A foul in which a defender pushes or shoves an offensive player in order to impede his/her movement or progress.  
Signal:  Sign a pushing motion with both palms facing opposite the chest.

A violation is defined as an infraction of the rules by the offensive team that does not result in a free throw; the ball is turned over to the opposing team for a throw in.  If there is a violation, the referee should blow the whistle sharply, and raise an open hand high in the air above the head.  Then the referee should make the appropriate hand signal that corresponds to the violation being committed. 

In younger leagues, quickly gather the players together and explain the violation, how it can be avoided, and the result of the violation. The extent of this explanation will vary according to the age and understanding of the players. Ideally, violation explanations will decrease as the season progresses.

Common Violation Hand Signal  Definitions

The following are definitions of common violations and their proper hand signals:

Traveling

When the ball handler takes more than the allotted steps (two) or moves the pivot foot without dribbling. A pivot is defined when a player with the basketball makes a step or multiple steps with one foot, the foot remaining stationary on the floor becomes the pivot and cannot be moved prior to a dribble. A traveling violation should also be called on a player who, while holding the basketball, falls to the court without maintaining the pivot foot.
Signal:  Rotate clenched fists and forearms around each other.

Double Dribble

Occurs when a player stops dribbling and then dribbles again without giving up possession, or when a player dribbles the ball with both hands at the same time. 
Signal:  Sign a patting motion in front of the body with one hand at a time.

Palming or Carrying the Ball 

When a player moves his/her hand under the ball and scoops it while dribbling.
Signal: Hold one arm to the side of the body as the other hand waves back and forth in a side-to-side motion.

Three-Seconds (3rd through 6th grade ONLY)

An offensive player can spend no more than three consecutive seconds within the free throw lane.  Keep in mind that each time a shot attempt is made, the three second count starts over. 
Signal:  Hold three fingers up in the air at shoulder level, then waving hand from shoulder to waist.

After the play has ended, the referee should address what occurred by:

• Quickly explaining the violation/foul to the players by telling them how it can be avoided and the result of the infraction. The extent of the explanation will vary according to the age and understanding of the players and should decrease as the season progresses.
• Communicating whether the consequence results in alternating possession (violation or non-shooting foul) or free throw attempts (shooting foul).