Table 5. Top 20 word groups derived from n-gram analysis.

Rank	Forest Operation		Forest Operation Safety
Rank	Words	Frequency	Words	Frequency
1	Production	17	Forest Management	14
1	Cost	17	Member	14
2	Harvesting	13	Adequacy	12
2	System	13	Wage	12
3	Forestry	12	Branch	10
3	Machinery	12	Removal	10
4	System	11	Construction Sector	10
4	Cost	11	Standard Wage	10
5	Biomass	11	Real	8
5	Usage	11	Time	8
6	Cost	10	Duty	8
6	Reduction	10	Satisfaction	8
7	Function	9	Production	8
7	Forest Management	9	Cost	8
8	Safety	9	Standard Wage	7
8	Awareness	9	Unit Price	7
9	Usage	8	Worker	7
9	Forwarding	8	Adequacy	7
10	Forwarding	8	Pulse	6
10	System	8	Intensity	6
11	Forwarding	8	Chainsaw	6
11	Production	8	Usage	6
12	Forest Road	8	Awareness	6
12	Facility	8	Level	6
13	Track-type	7	Measurement	6
13	Mini-Forwarder	7	Body Part	6
14	Forestry	7	Felling	6
14	Labor Force	7	Processing	6
15	Survey	7	Intensity	6
15	Result	7	Factor	6
16	Job	7	Walking	6
16	Stress	7	Intensity	6
17	Usage	7	Human	6
17	Process	7	Ergonomics	6
18	Reduction	7	Improvement	5
18	Efficiency	7	Solution	5
19	Complex	7	Posture	5
19	Work Equipment	7	Risk	5
20	Policy	6	Worker	5
20	Evaluation	6	Wage	5