This looks like them to me - 1911 census - although John's b.d. is a bit off. Three Harper families living next to one another. All b. Ontario, all English, all Presbyterian, all farming.

1911 / Alberta / Edmonton / 8 Townships 57 / page 13
41 36 Harper John M Head M Mar 1887 24
42 36 Harper Amelia F Wife M Dec 1892 18
43 36 Harper Hilliard M Son S Apr 1909 1

44 36 Harper Sam M Head M Dec 1846 64
45 37 Harper Mary F Wife M Jul 1845 65
46 37 Harper Ida F Daughter S Sep 1892 18

47 38 Harper George M Head M Aug 1875 37
48 38 Harper Sarah F Wife M May 1875 35
49 38 Harper Betty F Daughter S Jun 1895 15
50 38 Harper Char? M Son S Sep 1898 12

1901 Census
The b.d. are out a bit here too but I think this is the same family. All b. ON urban (probably Brockville) except father Samuel who was b. ON rural.
16 9 167 Harper James M Head M Feb 20 1872 29
16 10 167 Harper Alice F Wife M not known 1876 24
16 11 167 Harper J. Samuel M Father M Aug 29 1851 49
16 12 167 Harper Mary E. F Mother M Jul 4 1849 51
16 13 167 Harper Claude M Brother S Mar 10 1883 18
16 14 167 Harper John M Brother S Mar 10 1885 16
16 15 167 Harper Abe M Brother S Dec 27 1889 11
16 16 167 Harper Ida F Sister S Aug 11 1894 6
16 17 167 Harper Charles M Brother S Jan 13 1881 20

Living next door to
16 18 168 Harper George M Head M not known 1873 27
16 19 168 Harper Sarah A F Wife M May 28 1876 24
16 20 168 Harper Netta R F Daughter S Jun 2 1896 4
16 21 168 Harper Charles E. M Son S Sep 15 1898 2

1901 Census of Canada
Subdistrict: Brockville (Town/Ville) East/Est (Ward/Quartier), BROCKVILLE, ONTARIO
District Number: 47
Subdistrict Number: b-1
Archives Microfilm: T-6460