A method, comprising: at an electronic device with a display, a touch-sensitive surface, and one or more sensors to detect intensities of contacts with the touch-sensitive surface: detecting a first gesture that includes: detecting a first contact moving across the touch-sensitive surface, concurrently detecting a second contact moving across the touch-sensitive surface, wherein the first contact and the second contact move relative to each other across the touch-sensitive surface, detecting an intensity of the first contact, and detecting an intensity of the second contact; and, in response to detecting the first gesture: in accordance with a determination that the first gesture meets first operation criteria, performing a first operation, wherein the first operation criteria include that: the intensity of the first contact is greater than a respective intensity threshold, the intensity of the second contact is greater than the respective intensity threshold, and, a difference between the intensity of the first contact and the intensity of the second contact is less than a similarity threshold; and, in accordance with a determination that the first gesture meets second operation criteria that are distinct from the first operation criteria, performing a second operation that is different from the first operation, wherein: the second operation criteria are met when the difference between the intensity of the first contact and the intensity of the second contact is greater than the similarity threshold, and the second operation criteria are capable of being met when the intensities of the first and second contacts are less than the respective intensity threshold. detecting a first gesture that includes: detecting a first contact moving across the touch-sensitive surface, concurrently detecting a second contact moving across the touch-sensitive surface, wherein the first contact and the second contact move relative to each other across the touch-sensitive surface, detecting an intensity of the first contact, and detecting an intensity of the second contact; and, detecting a first contact moving across the touch-sensitive surface, concurrently detecting a second contact moving across the touch-sensitive surface, wherein the first contact and the second contact move relative to each other across the touch-sensitive surface, detecting an intensity of the first contact, and detecting an intensity of the second contact; and, in response to detecting the first gesture: in accordance with a determination that the first gesture meets first operation criteria, performing a first operation, wherein the first operation criteria include that: the intensity of the first contact is greater than a respective intensity threshold, the intensity of the second contact is greater than the respective intensity threshold, and, a difference between the intensity of the first contact and the intensity of the second contact is less than a similarity threshold; and, in accordance with a determination that the first gesture meets second operation criteria that are distinct from the first operation criteria, performing a second operation that is different from the first operation, wherein: the second operation criteria are met when the difference between the intensity of the first contact and the intensity of the second contact is greater than the similarity threshold, and the second operation criteria are capable of being met when the intensities of the first and second contacts are less than the respective intensity threshold. in accordance with a determination that the first gesture meets first operation criteria, performing a first operation, wherein the first operation criteria include that: the intensity of the first contact is greater than a respective intensity threshold, the intensity of the second contact is greater than the respective intensity threshold, and, a difference between the intensity of the first contact and the intensity of the second contact is less than a similarity threshold; and, the intensity of the first contact is greater than a respective intensity threshold, the intensity of the second contact is greater than the respective intensity threshold, and, a difference between the intensity of the first contact and the intensity of the second contact is less than a similarity threshold; and, in accordance with a determination that the first gesture meets second operation criteria that are distinct from the first operation criteria, performing a second operation that is different from the first operation, wherein: the second operation criteria are met when the difference between the intensity of the first contact and the intensity of the second contact is greater than the similarity threshold, and the second operation criteria are capable of being met when the intensities of the first and second contacts are less than the respective intensity threshold. the second operation criteria are met when the difference between the intensity of the first contact and the intensity of the second contact is greater than the similarity threshold, and the second operation criteria are capable of being met when the intensities of the first and second contacts are less than the respective intensity threshold.