Pure ALOHA has less delay than Slotted ALOHA at low load.

Reasoning:

In pure ALOHA, a station transmits a frame the instant it becomes ready, with no waiting for any external timing signal.

In slotted ALOHA, time is divided into discrete slots (equal to one frame transmission time), and a station must wait until the start of the next slot boundary before it's allowed to transmit — even if the frame was ready earlier.

At low load, collisions are rare in both schemes (few stations contending), so the throughput/success-rate difference between the two barely matters. What dominates delay at low load is simply how long a station has to wait before it's permitted to send:

• Pure ALOHA: transmits immediately upon readiness — zero extra waiting time.
• Slotted ALOHA: must wait, on average, half a slot time (frame transmission time) for the next slot boundary to arrive, even when there's no contention at all.

So at low load, pure ALOHA's average access delay is lower simply because it doesn't impose the slot-alignment waiting overhead that slotted ALOHA requires — the throughput advantage of slotted ALOHA (from fewer collisions) only becomes the dominant factor at higher loads, where collision avoidance matters more than the small alignment delay.