Average basket size refers to the number of items getting sold in a single purchase. This is an excellent support metric for AOV as it can provide context behind why AOV is either increasing or decreasing. [1]
[1] 6 Retail Metrics You Absolutely Need to Track for Your Store. Retrieved May 21, 2021, from https://bindopos.com/blog/6-retail-metrics-to-track-monitor-for-your-store/
[2] Average Basket Size. Retrieved May 21, 2021, from https://www.klipfolio.com/metrics/marketing/average-basket-size