Computer implemented method for determining an activity of an occupant of a vehicle, the method comprising the following steps carried out by computer hardware components: - capturing sensor data of the occupant using at least one sensor; - determining respective coordinates for a plurality of pre-determined portions of the body of the occupant (308, 310) based on the sensor data, and including positional data in a feature vector; - determining at least one portion of the sensor data (108, 304, 306) showing a pre-determined body part of the occupant based on the sensor data and the coordinates, and encoding content of the sensor data into further feature vectors (806, 808); - appending the further feature vectors and the feature vector to obtain a joined feature vector; and - determining the activity of the occupant based on the joined feature vector; wherein determining the activity comprises classifying an action of a driver into one or more classes of a plurality of classes of actions; and wherein classifying comprises determining a probability vector, wherein each entry of the probability vector indicates a respective probability for each class of the plurality of classes of actions; characterised in that said coordinates are three-dimensional coordinates and the positional data included in the feature vector are the three-dimensional coordinates. a vehicle, the method comprising the following steps carried out by computer hardware components: - capturing sensor data of the occupant using at least one sensor; - determining respective coordinates for a plurality of pre-determined portions of the body of the occupant (308, 310) based on the sensor data, and including positional data in a feature vector; - determining at least one portion of the sensor data (108, 304, 306) showing a pre-determined body part of the occupant based on the sensor data and the coordinates, and encoding content of the sensor data into further feature vectors (806, 808); - appending the further feature vectors and the feature vector to obtain a joined feature vector; and - determining the activity of the occupant based on the joined feature vector; - capturing sensor data of the occupant using at least one sensor; - determining respective coordinates for a plurality of pre-determined portions of the body of the occupant (308, 310) based on the sensor data, and including positional data in a feature vector; - determining at least one portion of the sensor data (108, 304, 306) showing a pre-determined body part of the occupant based on the sensor data and the coordinates, and encoding content of the sensor data into further feature vectors (806, 808); - appending the further feature vectors and the feature vector to obtain a joined feature vector; and - determining the activity of the occupant based on the joined feature vector; wherein determining the activity comprises classifying an action of a driver into one or more classes of a plurality of classes of actions; and wherein classifying comprises determining a probability vector, wherein each entry of the probability vector indicates a respective probability for each class of the plurality of classes of actions; characterised in that said coordinates are three-dimensional coordinates and the positional data included in the feature vector are the three-dimensional coordinates.