A method of operating an electronic device comprising a touch-sensitive surface (112, 355, 451) and a display (112, 340, 450), wherein the device includes one or more sensors to detect intensities of contacts on the touch-sensitive surface, the method comprising the steps of: displaying a user interface (138A-02, 138B-02, 138C-02) on the display, wherein the user interface is set in a first display state; detecting a gesture (138A-08, 138B-08, 138C-08) on the touch-sensitive surface, the step of detecting the gesture including detecting an intensity of a respective contact on the touch-sensitive surface, wherein intensity of the respective contact is the force or pressure of the respective contact or a proxy for the force or pressure of the respective contact; the method charaterised by comprising the steps of: in response to detecting an increase in the intensity, including an increase over a first threshold of the respective contact, displaying a plurality of intermediate display states (S1', I-a, I-b, I-c) between the first display state and a second display state including displaying a first intermediate display state followed by displaying a second intermediate display state; after displaying the first intermediate display state, continuing to detect the intensity of the respective contact on the touch-sensitive surface; and detecting a decrease in the intensity of the respective contact below the first intensity threshold; in accordance with a determination that the intensity of the respective contact reached a predefined intensity threshold (IT L), displaying the second display state, and maintaining display of the second display state as the intensity of the respective contact decreases; in accordance with a determination that the intensity of the respective contact did not reach the predefined intensity threshold (IT L), replacing display of the second intermediate display state with display of a further intermediate display state, among the plurality of intermediate display states, as the intensity of the respective contact decreases; and in response to detecting liftoff of the contact: in accordance with the determination that the intensity of the respective contact reached the predefined intensity threshold (IT L), maintaining display of the second display state; and in accordance with the determination that the intensity of the respective contact did not reach the predefined intensity threshold (IT L), terminating display of the intermediate display state and redisplaying the first display state, wherein the predefined intensity threshold (IT L) is higher than the first intensity threshold. displaying a user interface (138A-02, 138B-02, 138C-02) on the display, wherein the user interface is set in a first display state; detecting a gesture (138A-08, 138B-08, 138C-08) on the touch-sensitive surface, the step of detecting the gesture including detecting an intensity of a respective contact on the touch-sensitive surface, wherein intensity of the respective contact is the force or pressure of the respective contact or a proxy for the force or pressure of the respective contact; in response to detecting an increase in the intensity, including an increase over a first threshold of the respective contact, displaying a plurality of intermediate display states (S1', I-a, I-b, I-c) between the first display state and a second display state including displaying a first intermediate display state followed by displaying a second intermediate display state; after displaying the first intermediate display state, continuing to detect the intensity of the respective contact on the touch-sensitive surface; and detecting a decrease in the intensity of the respective contact below the first intensity threshold; in accordance with a determination that the intensity of the respective contact reached a predefined intensity threshold (IT L), displaying the second display state, and maintaining display of the second display state as the intensity of the respective contact decreases; in accordance with a determination that the intensity of the respective contact did not reach the predefined intensity threshold (IT L), replacing display of the second intermediate display state with display of a further intermediate display state, among the plurality of intermediate display states, as the intensity of the respective contact decreases; and in response to detecting liftoff of the contact: in accordance with the determination that the intensity of the respective contact reached the predefined intensity threshold (IT L), maintaining display of the second display state; and in accordance with the determination that the intensity of the respective contact did not reach the predefined intensity threshold (IT L), terminating display of the intermediate display state and redisplaying the first display state, wherein the predefined intensity threshold (IT L) is higher than the first intensity threshold. in accordance with the determination that the intensity of the respective contact reached the predefined intensity threshold (IT L), maintaining display of the second display state; and in accordance with the determination that the intensity of the respective contact did not reach the predefined intensity threshold (IT L), terminating display of the intermediate display state and redisplaying the first display state, wherein the predefined intensity threshold (IT L) is higher than the first intensity threshold.