Under what two circumstances would you recommend against the use of ABBA counterbalancing to balance practice effects in a repeated measures experiment using a complete design? Briefly describe the...

Under what two circumstances would you recommend against the use of ABBA counterbalancing to balance practice effects in a repeated measures experiment using a complete design?

Briefly describe the techniques that researchers can use to balance practice effects in the repeated measures experiments using an incomplete design. Identify which of these techniques is preferred and explain why.