# Development and Reliability of a Street Skateboarding Notational Analysis Framework and Application
## 2 Materials and Methods
### Procedures  
#### 2.3.1 Data Preparation and Notational Analysis  
To capture potential outcome-related aspects of street skateboarding, a custom NA application was designed using MATLAB (MathWorks Inc. (2021b). MATLAB version: 9.11.0 (R2021b), Natick, MA, USA: The MathWorks Inc.) (Figure 3). Importantly, the NA framework we present is independent from this particular software, and the system could be implemented using other platforms or tools. Broadcast footage was clipped into separate videos for each BT and RUN, and subsequently loaded into the application, featuring two video viewing windows, each displaying the video selected (A) from the file selection panel  
\begin{table}
\begin{tabular}{l c c c c} \hline \hline \multicolumn{5}{c}{**TA Distinct Time Points**} \\ \cline{2-5}
**Obstacle\({}_{\text{IA}}\) and TO-IA Transition \({}^{\ast}\)** & **Take-Off** & **Event/Interaction** & **Event/Interaction End** & **Landing (\(Frame_{\text{LO}}\))** \\  & **(\(Frame_{\text{TO}}\))** & **(\(Frame_{\text{LO}\text{-Start}}\))** & **(\(Frame_{\text{LO}\text{-Start}}\))** & **(\(Frame_{\text{LO}\text{-Start}}\))** & **Landing (\(Frame_{\text{LO}}\))** \\ \hline \hline
**obstacle\({}_{\text{IA}}\) = Not Applicable:** & & & & \\ TAs that only interact with obstacles & & & & \\ during TO and LD (not IA) (e.g., \(\prime\) & & & & \\ fundamental, flip, air/grab, balance, etc.) & Frame prior to board & & & \\  & completely leaving & & & \\ \hline
**obstacle\({}_{\text{IA}}\) = Applicable; Clear TO-IA** & & & & \\ TAs that interact with obstacle (other than air) during IA phase (e.g., grind, slide, stall) & & & & \\ \hline
**obstacle\({}_{\text{IA}}\) = Applicable; NOT Clear** & & & & \\ \multicolumn{5}{c}{**TO-IA**} & & & \\ TAs that interact with obstacle (other than air) during IA phase, but with no clear & Frame before board & & & \\ \multicolumn{5}{c}{**TO-IA**} & & & \\ \multicolumn{5}{c}{**TO(B) and the trick selection panel (C), respectively. The trick selection panel was accompanied by buttons for frame selection (D), and a panel for trick and obstacle classification (E). The application included buttons for TA tagging (F) and an athlete details panel (G). Attributes related to that BT or RUN clip were entered (skater and select action attributes). Then, each individual TA was tagged (as above) (F), and a trimmed video clip (H) was created capturing one second before and after the TA frame. A rater could then label each TO, IA (start and end), and LD phase, respectively, capturing action (E), position (J), and outcome metrics (K) to identify that TA. For intra-rater reliability, one rater (R1) coded all video clips on two occasions (R1\({}_{1}\) and R1\({}_{2}\)), at least two weeks apart. For inter-reliability, three raters (R1, R2, and R3) coded all video clips in a different order. Specifically, raters coded TAs in alphabetical order by skater first name (or reverse alphabetical order). Thus, each coded all TAs from an individual skater before moving on to another skater.  
Trick classification was conducted independently by two authors, who were experienced in classifying skateboarding tricks, skaters themselves for at least 5 years, and were familiar with skating terminology. The reliability of trick naming and coding was not assessed; however, any disagreements in trick classification or TA outcome (e.g., whether hand drag during RUN TA was landed or bailed) were discussed together and final decisions and underpinning reasonings were provided in Section 4.