CERTIFICATION PURSUANT TO SECTION 302 OF
                        THE SARBANES-OXLEY ACT OF 2002

I, David P. Butler, certify that:

1. I have reviewed this report on Form N-CSR/A of Dimensional Investment Group
   Inc. (the "Registrant");

2. Based on my knowledge, this report does not contain any untrue statement of
   a material fact or omit to state a material fact necessary to make the
   statements made, in light of the circumstances under which such statements
   were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial
   information included in this report, fairly present in all material respects
   the financial condition, results of operations, changes in net assets, and
   cash flows (if the financial statements are required to include a statement
   of cash flows) of the Registrant as of, and for, the periods presented in
   this report;

4. The Registrant's other certifying officers and I are responsible for
   establishing and maintaining disclosure controls and procedures (as defined
   in Rule 30a-3(c) under the Investment Company Act of 1940, as amended) and
   internal control over financial reporting (as defined in Rule 30a-3(d) under
   the Investment Company Act of 1940, as amended) for the Registrant and have:

       a) designed such disclosure controls and procedures, or caused such
          disclosure controls and procedures to be designed under our
          supervision, to ensure that material information relating to the
          Registrant, including its consolidated subsidiaries, is made known to
          us by others within those entities, particularly during the period in
          which this report is being prepared;

       b) designed such internal control over financial reporting, or caused
          such internal control over financial reporting to be designed under
          our supervision, to provide reasonable assurance regarding the
          reliability of financial reporting and the preparation of financial
          statements for external purposes in accordance with generally
          accepted accounting principals;

       c) evaluated the effectiveness of the Registrant's disclosure controls
          and procedures and presented in this report our conclusions about the
          effectiveness of the disclosure controls and procedures, as of a date
          within 90 days prior to the filing date of this report based on such
          evaluation; and



       d) disclosed in this report any change in the Registrant's internal
          control over financial reporting that occurred during the second
          fiscal quarter of the period covered by this report that has
          materially affected, or is reasonably likely to materially affect,
          the Registrant's internal control over financial reporting; and

5. The Registrant's other certifying officers and I have disclosed to the
   Registrant's auditors and the audit committee of the Registrant's board of
   directors (or persons performing the equivalent functions):

       a) all significant deficiencies and material weaknesses in the design or
          operation of internal control over financial reporting which are
          reasonably likely to adversely affect the Registrant's ability to
          record, process, summarize, and report financial information; and

       b) any fraud, whether or not material, that involves management or other
          employees who have a significant role in the Registrant's internal
          control over financial reporting.

Date:  August 31, 2018

By:    /s/ David P. Butler
       ------------------------------------
       David P. Butler
       Co-Principal Executive Officer
       Dimensional Investment Group Inc.



                   CERTIFICATION PURSUANT TO SECTION 302 OF
                        THE SARBANES-OXLEY ACT OF 2002

I, Gerard K. O'Reilly, certify that:

1. I have reviewed this report on Form N-CSR/A of Dimensional Investment Group
   Inc. (the "Registrant");

2. Based on my knowledge, this report does not contain any untrue statement of
   a material fact or omit to state a material fact necessary to make the
   statements made, in light of the circumstances under which such statements
   were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial
   information included in this report, fairly present in all material respects
   the financial condition, results of operations, changes in net assets, and
   cash flows (if the financial statements are required to include a statement
   of cash flows) of the Registrant as of, and for, the periods presented in
   this report;

4. The Registrant's other certifying officers and I are responsible for
   establishing and maintaining disclosure controls and procedures (as defined
   in Rule 30a-3(c) under the Investment Company Act of 1940, as amended) and
   internal control over financial reporting (as defined in Rule 30a-3(d) under
   the Investment Company Act of 1940, as amended) for the Registrant and have:

       a) designed such disclosure controls and procedures, or caused such
          disclosure controls and procedures to be designed under our
          supervision, to ensure that material information relating to the
          Registrant, including its consolidated subsidiaries, is made known to
          us by others within those entities, particularly during the period in
          which this report is being prepared;

       b) designed such internal control over financial reporting, or caused
          such internal control over financial reporting to be designed under
          our supervision, to provide reasonable assurance regarding the
          reliability of financial reporting and the preparation of financial
          statements for external purposes in accordance with generally
          accepted accounting principals;

       c) evaluated the effectiveness of the Registrant's disclosure controls
          and procedures and presented in this report our conclusions about the
          effectiveness of the disclosure controls and procedures, as of a date
          within 90 days prior to the filing date of this report based on such
          evaluation; and



       d) disclosed in this report any change in the Registrant's internal
          control over financial reporting that occurred during the second
          fiscal quarter of the period covered by this report that has
          materially affected, or is reasonably likely to materially affect,
          the Registrant's internal control over financial reporting; and

5. The Registrant's other certifying officers and I have disclosed to the
   Registrant's auditors and the audit committee of the Registrant's board of
   directors (or persons performing the equivalent functions):

       a) all significant deficiencies and material weaknesses in the design or
          operation of internal control over financial reporting which are
          reasonably likely to adversely affect the Registrant's ability to
          record, process, summarize, and report financial information; and

       b) any fraud, whether or not material, that involves management or other
          employees who have a significant role in the Registrant's internal
          control over financial reporting.

Date:  August 31, 2018

By:    /s/ Gerard K. O'Reilly
       ------------------------------------
       Gerard K. O'Reilly
       Co-Principal Executive Officer
       Dimensional Investment Group Inc.



                   CERTIFICATION PURSUANT TO SECTION 302 OF
                        THE SARBANES-OXLEY ACT OF 2002

I, Gregory K. Hinkle, certify that:

1. I have reviewed this report on Form N-CSR/A of Dimensional Investment Group
   Inc. (the "Registrant");

2. Based on my knowledge, this report does not contain any untrue statement of
   a material fact or omit to state a material fact necessary to make the
   statements made, in light of the circumstances under which such statements
   were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial
   information included in this report, fairly present in all material respects
   the financial condition, results of operations, changes in net assets, and
   cash flows (if the financial statements are required to include a statement
   of cash flows) of the Registrant as of, and for, the periods presented in
   this report;

4. The Registrant's other certifying officers and I are responsible for
   establishing and maintaining disclosure controls and procedures (as defined
   in Rule 30a-3(c) under the Investment Company Act of 1940, as amended) and
   internal control over financial reporting (as defined in Rule 30a-3(d) under
   the Investment Company Act of 1940, as amended) for the Registrant and have:

       a) designed such disclosure controls and procedures, or caused such
          disclosure controls and procedures to be designed under our
          supervision, to ensure that material information relating to the
          Registrant, including its consolidated subsidiaries, is made known to
          us by others within those entities, particularly during the period in
          which this report is being prepared;

       b) designed such internal control over financial reporting, or caused
          such internal control over financial reporting to be designed under
          our supervision, to provide reasonable assurance regarding the
          reliability of financial reporting and the preparation of financial
          statements for external purposes in accordance with generally
          accepted accounting principals;

       c) evaluated the effectiveness of the Registrant's disclosure controls
          and procedures and presented in this report our conclusions about the
          effectiveness of the disclosure controls and procedures, as of a date
          within 90 days prior to the filing date of this report based on such
          evaluation; and

       d) disclosed in this report any change in the Registrant's internal
          control over financial reporting that occurred during the second



          fiscal quarter of the period covered by this report that has
          materially affected, or is reasonably likely to materially affect,
          the Registrant's internal control over financial reporting; and

5. The Registrant's other certifying officers and I have disclosed to the
   Registrant's auditors and the audit committee of the Registrant's board of
   directors (or persons performing the equivalent functions):

       a) all significant deficiencies and material weaknesses in the design or
          operation of internal control over financial reporting which are
          reasonably likely to adversely affect the Registrant's ability to
          record, process, summarize, and report financial information; and

       b) any fraud, whether or not material, that involves management or other
          employees who have a significant role in the Registrant's internal
          control over financial reporting.

Date:  August 31, 2018

By:    /s/ Gregory K. Hinkle
       ------------------------------------
       Gregory K. Hinkle
       Principal Financial Officer
       Dimensional Investment Group Inc.