# Intent to Adopt Location Sharing for Logging Safety Applications
## 2 Materials and Methods
### Data Analysis
Age and smartphone frequency were recoded numerically in the data set, with 1, 2, 3, 4, and 5 representing age categories of \"less than 20 years\", \"20-29 years\", \"30-39 years\", \"40-49 years\", and \"50 or more years\", respectively, and frequency values of \"never\", \"rarely\", \"often\", and \"always\" corresponding to 1, 2, 3, and 4, respectively. The sample for smartphone carriers included responses for only those individuals that indicated \"yes\" to a previous question on smartphone ownership; individuals who did not own smartphones were treated as _NA_ in R and omitted from the model. Regression analysis is frequently employed in TPB studies to assess if attitude, norms, or control correlate with intent [33; 35; 37; 49]. Since our data set did not meet all the assumptions of linear or multiple regression, we used non-parametric ordinal regression, which is appropriate for ordered, categorical data, such as Likert scaled survey responses. For each behavior, we tested the null hypothesis that there was not a significant correlation between attitude, norms, or control and intent. The only assumption of ordinal regression is that data demonstrate proportional odds, meaning the relationship (slope) between each pair of terms is the same. To avoid assumption violations for modeling of the second behavior (PLDs on workers and heavy equipment), we applied scale effects for the control term. Scale effects did not ameliorate violations for the third behavior (PLDs for general situational awareness); consequently, results for this particular model include assumption violations for the control variable. Measures of outcome likelihood (\"very unlikely\", \"somewhat unlikely\", \"unsure\", \"somewhat likely\", and \"very likely\") and value (\"very bad\", \"somewhat bad\", \"neutral\", \"somewhat good\", and \"very good\") were recoded bipolarly as \(-2\), \(-1\), \(0\), \(1\), and \(2\), respectively. This scoring system is recommended by [PERSON] [27] and is typical for TPB studies [34]. To express attitude as a single value across multiple possible outcomes, we calculated a total score by multiplying each outcome likelihood with each corresponding value and then summing across all seven outcomes. Scores for a single outcome could range from \(-4\) to \(4\), and total scores for an individual survey participant could range from \(-28\) to \(28\). Positive numbers represent situations in which desirable outcomes are likely to result from LS use or undesirable outcomes are avoided. Conversely, negative numbers signify that undesirable outcomes are likely or good outcomes are not. The higher the total score, the stronger the positive attitude toward LS safety behaviors. Measures of control (\"none\", \"some\", \"a lot\") were designated as 1, 2, and 3, respectively. Norm responses were numbered 1, 2, 3, 4, and 5 for \"very unlikely\", \"somewhat unlikely\", \"unsure\", \"somewhat likely\", and \"very likely\", respectively. Since the survey measured attitude and control of a single, inclusive behavior (using PLDs on logging operations), all behaviors had one total attitude score and one control score. Each of the three behaviors had a separate norm and intent score.