Abstract: Persistent storage contains a training dataset and a test dataset, each with units of text labelled from a plurality of categories. A machine learning model has been trained with the training dataset to classify input units of text into the plurality of categories. One or more processors are configured to: read the training dataset or the test dataset; determine distributional properties of the training dataset or the test dataset; determine, using the machine learning model, saliency maps for tokens in the training dataset or the test dataset; perturb, by way of token insertion, token deletion, or token replacement, the training dataset or the test dataset into an expanded dataset; obtain, using the machine learning model, classifications into the plurality of categories for the expanded dataset; and based on the distributional properties, the saliency maps, and the classifications, identify causes of failure for the machine learning model.

Abstract: A nozzle for attachment to a hair dryer includes a body and an airflow guiding member. The body has an internal surface which defines an airflow duct which extends from an air inlet end for receiving an airflow to a slot-shaped air outlet end of the body. The internal surface has opposing first surface sections which taper inwardly towards the air outlet end, and opposing second surface sections which taper outwardly towards the air outlet end. The airflow guiding member guides a first portion of a received airflow towards one of the second surface sections, and a second portion of the received airflow towards the other of the second surface sections.

Abstract: A diffuser includes an air inlet for receiving an airflow from a hair dryer, an external grille having a plurality of air outlets for emitting at least part of the airflow from the diffuser, and an internal grille located between the air inlet and the external grille.

Abstract: A nozzle for attachment to a hair dryer includes a body and an airflow guiding member. The body has an internal surface which defines an airflow duct which extends from an air inlet end for receiving an airflow to a slot-shaped air outlet end of the body. The internal surface has opposing first surface sections which taper inwardly towards the air outlet end, and opposing second surface sections which taper outwardly towards the air outlet end. The airflow guiding member guides a first portion of a received airflow towards one of the second surface sections, and a second portion of the received airflow towards the other of the second surface sections.

Abstract: A diffuser includes an air inlet for receiving an airflow from a hair dryer, an external grille having a plurality of air outlets for emitting at least part of the airflow from the diffuser, and an internal grille located between the air inlet and the external grille.