stats.md

Amazon Reviews 2023 — Processed Dataset Statistics

Protocol: official rating_only -> iterative 5-core -> leave-one-out split -> sequential history at maxlen 20 & 50 -> item metadata join. All outputs are JSONL.

Category	#Users	#Items	#Interactions	Avg len	Median	Sparsity	Items w/ meta
Video_Games	94,762	25,612	814,586	8.5961	6	0.99966437	25,612 (100%)
Industrial_and_Scientific	50,985	25,848	412,947	8.0994	6	0.99968665	25,848 (100%)
Beauty_and_Personal_Care	729,576	207,649	6,624,441	9.0799	7	0.99995627	207,649 (100%)
Musical_Instruments	57,439	24,587	511,836	8.9109	7	0.99963757	24,587 (100%)
Books	776,370	495,063	9,488,297	12.2214	7	0.99997531	495,063 (100%)

Leave-one-out split row counts

Category	direct train	valid	test	seq20 train	seq50 train
Video_Games	625,062	94,762	94,762	530,300	530,300
Industrial_and_Scientific	310,977	50,985	50,985	259,992	259,992
Beauty_and_Personal_Care	5,165,289	729,576	729,576	4,435,713	4,435,713
Musical_Instruments	396,958	57,439	57,439	339,519	339,519
Books	7,935,557	776,370	776,370	7,159,187	7,159,187

Validation vs official 5-core

Category	my 5core	official	match	my #test	official #test	match
Video_Games	814,586	814,586	OK	94,762	94,762	OK
Industrial_and_Scientific	412,947	412,947	OK	50,985	50,985	OK
Beauty_and_Personal_Care	6,624,441	6,624,441	OK	729,576	729,576	OK
Musical_Instruments	511,836	511,836	OK	57,439	57,439	OK
Books	9,488,297	9,488,297	OK	776,370	776,370	OK