sqlxtract report main and understanding "Observation"

hello gurus,

     I try to understand the parts 'observation' in my sqltxtract's report main the in 'Observation' I do not understand and meaning of :

First Part:

DBMS_STATS

SYSTEM STATISTICS

Single-block read time of .756 milliseconds seems too small.

[-] Consider gathering workload system statistics using SYS.DBMS_STATS.GATHER_SYSTEM_STATS or adjusting SREADTIM using SYS.DBMS_STATS.SET_SYSTEM_STATS. See also MOS Doc ID 465787.1.

and second parts

DBMS_STATS

SYSTEM STATISTICS

Multi-block read time of 1.231 milliseconds seems too small.

[-] Consider gathering workload system statistics using SYS.DBMS_STATS.GATHER_SYSTEM_STATS or adjusting MREADTIM using SYS.DBMS_STATS.SET_SYSTEM_STATS. See also MOS