It’s springtime when CBS traditionally experiments with one-off scheduling tweaks that inform the network brass’ fall schedule decisions come May.

CBS tested sophomore comedy Mom in the anchor Thursday 9 PM slot last night. So far, Mom has been a hammock show, most recently following The Big Bang Theory at 8:30 PM and a Big Bang Theory repeat at 9:30 PM this season. Two seasons in, it is logical for CBS to consider Mom a potential tentpole and launching pad for new comedy series. Last night’s low-key test was inconclusive, with the Anna Faris-Allison Janney show drawing a 2.0 among adults 18-49 in Live+Same Day, matching its rating from last week when it followed a Big Bang repeat (1.8). This time, Mom aired behind a new Odd Couple (2.1). The Odd Couple and Mom are not particularly compatible, so it’s hard to draw conclusions, but Mom has been pretty consistent this season, holding well in the move from 8:30 PM to 9:30 PM and now 9 PM, so the mother-daughter sitcom, already renewed for next season, appears to be a potential solid utility player for CBS that could work in different slots.

CSI Cyber Patricia ArquetteOn April 21, CBS will air an original of CSI: Cyber in the Tuesday 10 PM slot. That is in addition to the CSI: Cyber original that will run the following night in the show’s regular Wednesday 10 PM slot. Cyber will replace a Person of Interest repeat that was to air on April 21 as part of an all-rerun Wednesday lineup. The decision to put an original Cyber on Wednesday stems in part from the fact that the network has a lot of originals as the crime drama started late. But because it launched so late, any additional exposure will also provide useful feedback for CBS.

The jury is still out of Cyber. After being pre-empted for The Doveskeeprs, the spinoff came back this week even with its last airing, an OK not great 1.5 in 18-49 (Live+same day). The latest offshoot in the CSI franchise has been well received by critics, and it boasts newly minted Oscar winner Patricia Arquette as the star. But it has not been a ratings breakout, and CBS may not have room for both the mothership CSI series and Cyber next season, so the network executives may be facing some tough decisions in the next few weeks.