- summary learn command documentation
Set the parameters for chunking.
|| `l` || `learn` ||
|| `-e, --enable, --on` || Turn chunking on. Can be modified by `-a` or `-b`. || || `-d, --disable, --off` || Turn all chunking off. (default) || || `-E, --except` || Learning is on, except as specified by RHS `dont-learn` actions. || || `-o, --only` || Chunking is on only as specified by RHS `force-learn` actions. || || `-l, --list` || Prints listings of `dont-learn` and `force-learn` states. || || `-a, --all-levels` || Build chunks whenever a subgoal returns a result. Learning must be enabled. || || `-b, --bottom-up` || Build chunks only for subgoals that have not yet had any subgoals with chunks built. Learning must be enabled. || || `-n, --local-negations` || Build chunks when local negation encountered in backtraces. (default) || || `-N, --no-local-negations` || Do not build chunks when local negation encountered in backtraces. || || `-p, --desirability-prefs` || Add relevant desirability preferences to backtraces. || || `-P, --no-desirability-prefs` || Do not add any desirability preferences to backtraces. (default)||
The learn command controls the parameters for chunking. With no arguments, this command prints out the current learning environment status. If arguments are provided, they will alter the learning environment as described in the options and arguments table. The [cmd_watch] command can be used to provide various levels of detail when productions are learned. Learning is _disabled_ by default.
With the `--on` flag, chunking is on all the time. With the `--except` flag, chunking is on, but Soar will not create chunks for states that have had RHS `dont-learn` actions executed in them. With the `--only` flag, chunking is off, but Soar will create chunks for only those states that have had RHS `force-learn` actions executed in them. With the `--off` flag, chunking is off all the time.
The `--only` flag and its companion `force-learn` RHS action allow Soar developers to turn learning on in a particular problem space, so that they can focus on debugging the learning problems in that particular problem space without having to address the problems elsewhere in their programs at the same time. Similarly, the `--except` flag and its companion `dont-learn` RHS action allow developers to temporarily turn learning off for debugging purposes. These facilities are provided as debugging tools, and do not correspond to any theory of learning in Soar.
The following final six settings are orthogonal to the `--on`, `--except`, `--only`, and `--off` flags, and so, may be used in combination with them.
The `--all-levels` and `--bottom-up` control when chunks are formed when there are multiple levels of subgoals. With bottom-up learning, chunks are learned only in states in which no subgoal has yet generated a chunk. In this mode, chunks are learned only for the "bottom" of the subgoal hierarchy and not the intermediate levels. With experience, the subgoals at the bottom will be replaced by the chunks, allowing higher level subgoals to be chunked.
The options `--local-negations` and `--no-local-negations` control whether or not chunks can be created that are derived from rules that check for negated WMEs on the substate (local negations). Chunking through local negations can result in overgeneral chunks, but disabling this ability will reduce the number of chunks formed. The default is to enable chunking through local negations.
If chunking through local negations is disabled, to see when chunks are discarded (and why), set `watch --learning print` (see [cmd_watch] command).
The options `--desirability-prefs` and `--no-desirability-prefs` control whether or not desirability preferences are added to the context dependent preference set, which is the set of operator evaluation preferences that led to the selection of an operator in a subgoal. All preferences in the CDPS are backtraced through when creating justifications and chunks. When this option is disabled, only requirement preferences (requires and prohibits) will be added to the CDPS. When this option is enabled, relevant desirability prefs (better, best, worse, worst, indifferent) will also be added, producing more specific and possibly correct chunks. The default is to not include desirability preferences.
Learning can be turned on or off at any point during a run.
To enable learning only at the lowest subgoal level:
To see all the `force-learn` and `dont-learn` states registered by RHS actions
[cmd_watch] [cmd_explain_backtraces] [cmd_save_backtraces]