Okay so I'll probably make a master-post about the APTI, I just have to know where exactly.
First of all, there are no real equivalents with MBTI/Enneagram/Socionics types, but we can try and identify some aspects of each type to different functions and nature of other typology indicators.
To make it short, the APTI is based on four letters :
E, V, L and F
E meaning Emotion, it's the attitude related to emotions, ethics, culture, desire and art. It's heavily linked to the awareness of our own emotions and also other's.
V meaning "Volition", it's the attitute related to identity, willpower, confidence, selfcontrol and control. It's heavily linked to leadership abilities and behaviour towards it.
L meaning Logic, it's the attitude related to knowledge, research of truth, proofs and analysis. It's heavily linked to your role in debates.
F meaning "Physics", it's the attitude related to food, looks, comfort, belongings, aesthetics and practical skills. It's heavily linked to the relationship with your environment and how it affects you.
Each position has its importance as well.
If the attitude is in the first position, it's Confident. This attitude is focussed on the results and is naturally aggressive due to the affinity you have with it and the tendency to distrust others when they're using that attitude. It's strong and assertive.
If the attitude is in the second position, it's Flexible. This attitude is process oriented and is naturally passive due to the openness it presents, compared to the first function. The Flexible attitude is cultivated with interest and is generally pretty well developped as well. The main difference with the Confident attitude is that it's willing to help and include others, being more open to change. It's strong and passive.
If the attitude is in the third position, it's Insecure. This attitude is process oriented and is naturally aggressive due to the distrust and apprenhension the individual feels towards the aspects of the attitude. It's either very avoidant or overly involved. It's weak and aggresive.
If the attitude is in the fourth position, it's Oblivious. This attitude is goal oriented and naturally passive due to the uninterest the individual has towards it until it must be dealt with to achieve desired results. There is an uninvolvement and oblivousness towards the attitude and the individual generally lets people do it at their place if it's possible. It's weak and passive.
Don't forget to check this website my friend created, it has a lot of info and there are short and long tests :
[I'll post it as soon as I get to 15 posts...]