Ma-Ai, distance, refers to the space between the Shidachi and Uchidachi. The stick is versatile, flexible and advantageous over the sword because of its longer length. However, there is NO EFFECT if the distance is too short or too long:  Too short and the Shidachi gets cut by the sword; too long and there is no impact.

Ri-Ai, timing, is the second crucial element, and both are necessary.  Good timing without proper distance is ineffective.  Perfect distance and poor timing is no good either.  Together, distance and timing make the Jo a formidable and powerful weapon.

You are not doing yourself or your partner any favors by missing when you strike.  If you deliberately try to avoid hitting the other person, you are not being effective.  Consider Boxers:  How long would a boxer last in the ring if they tried to avoid hitting their opponent?  Remember that Jodo is meant to be effective and that requires 2 things:  Distance (Ma-ai) and Timing (Ri-ai).

A definition of Zanshin is, "being in the moment." It is a state of pure concentration and total awareness as opponents face each other and spar.

There are different levels of intensity. Have you ever heard someone say something like, "Just one look from that guy will stop you dead in your tracks"?  It is the energy of this kind of intense focus that explains how someone can "dominate another person`s spirit and subdue them."

Keep your eyes and 100% of your concentration on your opponent at all times.  Many people make the mistake of relaxing and losing focus before and after a kata.  Even while doing "Osame" I have had partners that relaxed their concentration and even started goofing around.

Jo and Tachi are both weapons.  Never let down your guard.  Always be watching.  Stay focused.  Uchidachi is always looking for a way to get the advantage over Shidachi.  Likewise, Shidachi is always looking for a way to "BONK" Uchidachi.  

Me Tsuke, the act of threatening an opponent with the Jo pointed between opponent`s eyes, is an example of Zanshin in action.

Effective posture - includes not only your stance, but your attitude and bearing as well.

Ki-ai is "Eh" when striking, and "Ho" when thrusting. 

There are several reasons for Ki-ai:

1.  Safety - for your opponent and others that may be practicing nearby.

2.  Exhale - Ki-Ai at the time of impact forces the person to exhale while releasing all their energy and power at once. It is dangerous to hold your breathe when sparring; at risk of doing the Valsalva Maneuver.  

3.  Get Psyched - Ki-Ai is a way to self-encourage, overcome fear, and commit all out to the action.

Maintaining an unshakable spirit of calmness. Set your mind, be determined, rooted and stable both mentally and physically. Please read: http://en.wikipedia.org/wiki/Fudoshin

6. Junanshin, 柔軟心

Keep a flexible, open mind. This requires patience, the ability to set aside your opinions, previous experiences and biases, and a passion to learn. Develop a mental state of allowing - an attitude of no resistance.

7. Nintai, 忍耐

An attitude that combines perseverance, persistence, and tenacity. Hold fast to your course of action and your beliefs. Be relentless!

A pure mental state, completely empty of self (ego), emotion, thought. Please read: http://en.wikipedia.org/wiki/Mushin and http://en.wikipedia.org/wiki/Muga-mushin

An offensive attack using the Jo to threaten someone.

A counter-attack, which is distinctly different from a defensive reaction.  Sen no Sen involves knowing and predicting the opponents strategy and moves, identifying the weaknesses, and deliberately countering their move.  Note: The first Sen-no-sen technique is in Oshizume (Chudan Series).

A simultaneous, or mutual, attack. (This is a concept that is important to know but be aware that it is difficult to do, and does not happen within the practice of kata.)